S6225-HH-MMA-010_0_0_(2)___0508.pdf

APPROVAL AND PROCUREMENT RECORD PAGE

APPROVAL DATA FOR: NAVSEAS6225-HH-MMA-010

TITLE OF MANUAL: HOT WATER RECIRCULATING PUMP

APPROVAL AUTHORITY: Supervisor of Shipbuilding Conversion and Repair, USN P.O. Box 26 Sturgeon Bay, WI 54235

APPROVAL: SUPSHIP Ltr Ser 1490 dated 2 July 1981

NAVSEA NO:

QUANTITY QUANTITY

CONTRACT OR SHIP OF OF BUILDING

PURCHASE ORDER APPLICABLE MANUAL EQUIPMENT YARD

·N00024-78-C-2300 T-ATF 170-172 9 1 Per Ship Marinette Marine

P.O. #1260-1235 Corporation

NOTE:

DATE: 10 June 1981

CERTIFICATION:

IT IS HEREBY CERTIFIED THAT THIS MANUAL TO BE PROVIDED UNDER

CONTRACT N00024-78-C-2300 HAS BEEN APPROVED BY APPROVAL DATA

SHOWN ABOVE.

(signature~ir

Supervisor, Contract Administration (typed name and title)

I'

I e r----r~ AURORA PUMP

~ A UNIT OF GENERAL SIGNAL

NO. OF PRINTS

FOR APPROVAL

\0 FINAL

SALES OfFICE: A(A.rotf"o.. , M~lwCUA...(,{ee Po# 'MLSIJ-~1.-1

FACTORYORDERNUMBER: __ ,~~~\_-~C)~~~~~~~~--------------------------

JOB:

SERVICE: -------------------------------------------------------------

ENGINEER: -------------------------------------------------------------

CONTRACTOR: r---·--~~--~r---~~~----------------------~~~---=-- SOLD To: fJ\O..,-\V\eUe Mca-'M~ c;;o~ PO# ,Q(cl) ... \~ !>S

REFERENCE: ------------------------------------------------------------

PUMP

IW 0 NUMBER OF UNITS

___ ..-:5..._ __ GPM

\ )C \ kt...X 4 SIZE 5~ \ MODEL ---POWER SERIES PUMP ONLY 0

__ _.\ ..... ~----TDH \ JSJ) RPM ROTATION: RH g_-LH 0

BASE: CONSTRUCTION: COUPLING: STUFFING BOX: CONNECTIONS LUBRICATION

0 STEEL ~ANDARD 0 STANDARD ~ECHANICAL SEAL ~HREADED 0 GREASE

DRIP RIM FITTED

.STANDARD 0 STEEL 0 0 SPACER 0 FLANGE 0 OIL

0 FABRICATED CASE &J 0 GUARD 0 0 125#

STEEL IMP. 'I. 0 PACKING 0 250#

0 CAST IRON SHAFT ~s

RING TYPE SLEEVE 0 LANTERN RING 0

CASE RING ea._

IMP. RING--

MOTOR

HP. ___,~\-...~ _ PHASE c.o HERTZ \\SC?,ovoLTs \150 RPM S<. FRAME

BY: ~URORA

0 OTHERS

~DP 0 VERTICAL NOTE: MOTOR NOT MOUNTED

~ORIZONTAL ~Q.~f'~cL \t,C,. AT FACTORY ON . 0 TEFC

0 XPROOF 0 MANUF TURER VERTICAL UNITS.

PART WINDING

PUMP: ~.e <t'~S:

SPECIAL REQUIREMENTS

E~

DRIVE:

CERTIFIED SECTION: ao:l PAGE: =ao \ CURVE NUMBER: '3\~C!- \09\0 PRINT: SPECIAL: MAINTENANCE: ---:7'l'----------------

BY: 0. S AC-DATE: z.. 1 q ( Bl OFFICE: f\u,,-.0 'f""~

THIS O;DER WILL NOT BE ~CESSED FOR MANUFACTURING UNTIL APPROVAL IS RECEIVED.

PRINTS ARE NOT TO SCALE AND ARE CERTIFIED CORRECT ONLY FOR THIS ORDER. ALL

ORDERS SUBJECT TO ACCEPTANCE AT "'URORA PUMP, NORTH AURORA, ILLINOIS.

THIS ORDER CAN BE RELEASED FOR MANUFAQTURING AS SHOWN: 0

RELEASE FOR MANUFACTURING PER ATTACH~D CHANGE ORDER: 0

40130 (9-77)

AUTHORITY:------

OFFICE: ______ _

DATE:--------

..... --------AURORA MODEL 321 PUMPS--- SECTION 320 PAGE 201

DATED OCTOBER 1974

SUPERSEDES PAGE 201

DATED SEPTEMBER 1970

-ROTATION CC#

STANDARD POSITION (1)

1-------AG APPROX.-. ----+-

PUMP SIZE OPTIONAL DISCHARGE POSITIONS

CASE X y DC DO DE OF

DISCH SUCT BORE

';, 1 6 5'1z Pi, 3'.,. 3';,. 3' ' ., 2' 31

'I.. 1 7 6' ' .. 1'' ., 3 1s, 16 4 4';,, 21J, ' 16

1 1 ~~ 4 41 .' e 111 I

'" 2'~ 2'·~ 2';; , 21l . ' 16 1 1'~ 5 5 2 2 ll ; '16 2'' ., 3 2':, 1 1 I~ 6 51, 1 " ' ·I· 3'116 3'• e 3', 2';

11 .• 11., 5 5 1 ";16 2'1 2 ";.. 3 ':,. 2 , ,,.

1\ 1 12 7A 611.. 2 4 41 ·16 41/2 2" ' /16 1 I. 11 i 7B 6 I~ 2 '.;. 4 41 ' • 4' ' • 2';

11/ .. 11 ' 2 9 8 21/

'4 51' :

' 16 53/), 5 13 : ' 16 2'·a

1'1, 2 4 5 21· • 21 ' '2 3 2'1 .. 311\.

11/2 2 7 7 21<, 41' 16 41~ 4'8 2\

2 21;2 4 5 3'' 16 2\ 3 2 13; ,,. 3'.;.

2 21 ' •2 5 6 2" 16 3 3 l,,. 3' ;. 31,.

2 2 ~~ 6 6 2lf, 3 1/2 3" ! ' 16 4', 3

2 212 7 7 2"·' •• 4'.~. 4 '· 16 4 ~. 3';j, 3 3 6 8 3 s;. 3 'Ia '""'· 5 'Ia 3';.

POSITION (4)

NOTES

B D E F H AG BA

I, ALL DIMENSIONS IN INCHES,

FRAME A z. NOT ~OFt CONSTRUCTION PURPOSES UNLESS

CERTI~IED.

56 6 J~ 4 3 1•2 2',~. 1 1j2 11

.]2 SLOT 11 2 •;,,

3, CONDUIT BOX IS SHOWN IN APPROXIMATE LOCA-

TION, CAPACITOR WHEN ~URNISHED NOFtMALLY

143T 7 6 3 1/2 2'<. 2 11

;, SLOT 10 2 ~ APPEARS ON TOP OF MOTOR, DIMENSIONS ARE

145T 7 6 3 1;, 2 ~~ 2 I~ II ,, SLOT 11 2 ,, NOT SPECI~IED AS THEY VARY WITH EACH MOTOR

MANU~ACTUREFt, 182T 9 6 I~ 4 12 3'1 2'' ll 11 3'· .. DIMENSIONS MAY VARY ± 1/4", .. /4 l2

184T 9 7 1;; 4 I• 3'' 2 l r 4 "In 12 3 '•

5, CHECK DISCHARGE POSITION, C4SING 01MENSIONS

'2 .. WHICH EXCEED DIMENSION "0•• MAV RIEQUIR&:

PADS ~OR THE MOTOR.

AURORA PUMP

A UNIT CF GENERAL SIGNAL

800 AIRPORT ROAO•NORTH AURORA. ILLINOIS ·60542

DIMENSIONS .. · . : I •

SECTION 320 PAGE404 -----1 X 1-1/4 X 4 SERIES 320 ...... -----+-

DATED MARCH 1966 ENCLOSED IMPELLER

~rrrrrrrrrrrrrrrrrrrr1 rr~hHhHhHH-~1 k+-+-t--t----f--+-+-+++--H-+-l--+-+++l-+. -+--1 1--+-+-+++-+-+1-LI--+-+l1 i MAX. S PH E RES· 5 I 16 0 I A , • I , IMP. PATI. N0.·3vl-7-2 v ffi: ~.e++~'-""<-+-+-!-' +-+-+-+-+-+-li-+-+-+-+-+-+-+-+-._._+--+-' ....._..., -.--~~ CASE PA TI. NO.· 31 - 2 -tt!j:=tj~l'~~tt!j:j:jj

=ttt:t' !~tj'j·=ttt++-t-; -+f--ll----"ff~--+ MIN. IMP. DIA.· 2 IL r-... ' f-ltP+al_,rhr .. ~--+-~--o, 4~o~~;.:o+-+--+-+--+-._._+-+++-l--l-+-+-+-+-+--+--f- l----f- t·_,_ 1 1 v

1- ,... !/ ' 1':1 : ' j...·::.it.."'".,c~~, r-, +-+---rt--+-t--jl--1

W,_fv+-+++-l--l~I----~~~~G4~~1----+--+-+++~ '' ~~-+-+~H-+-+ ' r~~~-+.~1~+4-++++-+-+-H W I><..., I I ' ·r- ""' I i t.. 1--1. I V K~ r• ' 1 ' ~ i i t--t-t--j---1 rf.. k -'~' ! I J.;.1" I - ~~-t-+-·t--t---t-t---'-i ~ i' . Y 1 I • , 1 i

CAPACITY IN G. P. M. 31Pc-lo9o9 t-+--+-t-+--+-t-+--+--<f-+-+H'---+--+H'---+-+-+-+-+-+-f--t-+-L-l MAX. SPHERES· 5/16 0 I A ~-+-+--~-+-+--~-+-+--t-+--+--f-+--+--J--l-+--+-1--+-+---+-+----+---+--~ IMP. PA TI. N 0. · 31-7- 2 t-+--+-t-+--+--<1--+--+Hf--+--+--1-+-+H-+-+-+-+-+--+--+-+--+--+--l CASE PA TI. NO.· 31 - 2 - 2 ~-+--+-+-+-+-+--"c---+--+-+-+-+-+--~-- 1--+--!-+-+-+-+-+- •~ MIN. IMP. DIA.· 2 1/4

~1~=~~=~1~=~~~+-1 -+-~~f--_._-:-+-+---~~~~:=:=;=-~~-"-'-N-C~+-m:~'"'-+-':Oo~ES---"<,1 N1bT E ICi ~EI V4 HlP

1--+-1--+--j--!--+-1----+--+--+-~-l--+----l--l--1- -I-+- f-+-1--+-1-i -'~--+1 -+--1--l--1---1--+-1 t- ·- - +-+-+--1 f +-+-+--t-- t-- -' -t-- ·

~ ~ 2~ 214 I 2~

ChPACI ' JN G. P M.

AURORA PUMP

A UNIT 01" OaNaRAL SIGNAL CORI"ORATION

AURORA • ILLINOIS

SECTION 6 ITEM 321

DATED JUNE 1968

INSTRUCTION MANUAL

SERVICE

Your Aurora pump requires no maintenance other than periodic inspection and occasional cleaning.

The intent of inspection is to prevent breakdown, thus obtaining optimum service life. The pump is lubricated by the liquid being pumped and therefore does not require periodic lubrication. The motor, however may require lubrication, in which case, the motor manufacturer's recommendation should be followed.

REPAIRS

The pump may be disassembled using the illustra tions and text provided. Although complete disas sembly is covered, it will seldom be necessary to completely disassemble your Aurora pump.

The illustrations accompanying the disassembly in structions show the pump at various stages of dis assembly. The illustrations are intended to aid in the correct identification of the parts mentioned in the text.

Inspect removed parts at disassembly to determine their reusability. Cracked castings should never be reused. All packing and gaskets should be replaced with new ones at reassembly simply as a matter of economy; they are much less expensive to replace routinely than to replace as the need occurs. In gen eral it is economical to return to the manufacturer for repair only the motor and motor controller.

Disassembly of the Pump. Disassemble only what is needed to make repairs or accomplish inspection.

A . Pump casing r emoved.

REPAIR

MODEL 321 (GAHA)

B . Wearing r i n g rem oved f rom casing.

Proceed to disassemble the pump as follows: (See Figure 2.)

1. Remove the four nuts (1) or screws (2) and separate the pump casing (4), from seal bracket (18).

Tap the casing with a soft hammer to loosen it .

2. Unscrew the plugs (3) from the casing (4).

3. Use a puller to extract the wearing r ing (5) from pump casing.

C. Im pelle r with r e t a inin g sc r ew, washer, key, and " 0 " ring. Note seal s p ring in seal b racket.

@ 1968 AU RO R A PUMP

AURO RA• ILL-INO I S 1

NOTE

MODE/ ,32_1 ________________________________ ~~

The wearing ring (5) is pressed into the cas ing with a press fit. It is likely that during removal this fit will be lost. For this reason the wearing ring should never be removed from the casing unless it is to be replaced.

4. Remove studs (6) if pump is so equipped.

5. Remove screw (7) and washer (8) securing im peller (9) to the motor shaft.

6. Remove impeller (9) and key (10) from the motor shaft.

NOTE

A puller may be used to remove the impeller or it may be pried loose. Care should be taken that the impeller is not damaged during removal.

D. Seal spring removed with remaining seal part~ still on shaft.

7. Pry out "0" ring (12) only if it is damageJ .

8. Remove the pipe plug (13) from the se~l bracket.

9. Remove screws (16) and washers (17) if 1o equipped and carefully slide the seal bracket (18) a d mechanical seal (11) off the motor shaft.

NOTE

The seal spring can be removed prior to the removal of the seal bracket.

10. Carefully push the seal seat and cup out of ~e seal bracket. I

E. Seal bracket removed with seal drive ring, re tainer, and flexible bellows assembled and seal washer loose. Note s-eal cup and seat still in bracket.

The mechanical seal (see Figure 1) is a pre cision product and must be treated as such.

During removal great care must be taken to avoid dropping any part of the seal. Take particular care not to scratch the lapped faces on the washer on the sealing seat. Do not put a seal back into service until the seal ing faces of the washer and seat have been lapped or the washer and seat have been re placed.

12. Remove the pump nameplate (15) and screws

(14) only if replacement is necessary.

13. Remove rubber slinger (19) from motor shaft.

INSPECTION

When the pump is disassembled, the parts should be cleaned and inspected for damage. Specifically in spect:

1. The seal faces for chips, scratches and other damage that may have occured during removal. The seal faces are lapped surfaces and must be relapped or the washer and seat replaced before reassembly.

2. The seal cavity in the seal bracket for burrs or nicks that could damage the flexible cup of the seal.

3. The impeller hub and casing wearing ring for signs of excessive wear.

4. The "O" ring for abrasions, cuts or other dam age.

Also inspect all castings for cracks or other damage that could impair pump operation.

MODEL 321

REASSEMBLY

Reassembly of the pump will generally be in reverse order of disassembly, but not exactly so. If disas sembly was not complete use only those steps re lated to your particular repair program.

1. Position the pump bracket (18) on the motor and secure with washers (17) and screws (16).

Tighten screws evenly.

2. Install plug (13) to the seal bracket. Position "0" ring (12) on the seal bracket and gradually slip into its groove.

NOTE

The mechanical seal (11) (see Figure 1) can not be installed as an assembly. It is neces sary to have the seal seat properly in place before the balance of parts can be added.

3. Apply a film of liquid dishwashing detergent to the flexible cup and seal seat. Insert the seat in the cup and install in the pump bracket (18). If it is not possible to insert seat with fingers, place cardboard protecting ring, furnished with seal, over lapped face of seat and press into place with a piece of tubing having end cut square. Tubing should be slightly larger than the diameter of the shaft. Remove card board ring after seat is firmly seated.

4. Apply a film of liquid dishwashing detergent to the washer and bellows of the seal, and slide the re maining seal parts onto the shaft, making sure the washer is seated against the seal seat.

WASHER

Refer to figure 1 for correct assembly of seal parts.

5. Install !(ey {10) on shaft and assemble impeller (9). Be sure spring of mechanical seal is properly positioned on back side of impeller. Secure impeller with washer {8) and screw (7).

6. Assemble studs (6) if used, into pump casing.

7. Install the wearing ring (5) into the casing ( 4).

The wearing ring must be pressed into pump casing.

Do not attempt to hammer it into position. An arbor press would be ideal, however, placing a block of wood over the ring and pressing it in will work satis factorily.

Because the wearing ring is a press fit it must be given special care. Be sure the ring is positioned squarely over the casing bore.

With a soft hammer tap the ring gently so it enters the bore evenly.

8. Install two pipe plugs {3) in the pump casing.

Position the pump casing against the seal bracket and secure with screws (2) or nuts (1) as required.

9. Attach the nameplate {15) to the casing with screws (14) if it has been removed.

Starting Pump After Reassembly. Do not start pump until all air and vapor has been bled and making sure that there is liquid in the pump to provide the neces sary lubrication. It is possible that the mechanical seal may drip during first few minutes of operation.

Figure 1. Mechanical Seal

MODElL 321

------ ------ ------11 ---- ---

I I I I

BOLD FACE PIECE NUMBERS

INDICATE RECOMMENDED

SPARE PARTS

1. Nut

2. Capscrew

3. Pipe Plug

4. Casing

5. Wearing Ring

6. Stud

7. Capscrew

8, Washer

9. Impeller

10. Key lL. Seal 1~. Gasket

13. Pipe Plug

Figure 2. GAHA Pump Exploded View

NOTE

WHEN ORDERING SPARE PARTS ALWAYS INCLUDE THE PUMP

TYPE, SIZE, SERIAL Nl~MBER, AND THE PIECE NUMBER FROM

THE EXPLODED VIEW IN THIS MANUAL.

-- ---J

14. Screw

15. Nameplate

16. Capscrew

17. Washer

18. Bracket

19. Slinger

ORDER ALL PARTS FROM YOU~ LOCAL AUTHORIZED DISTRIBUTOR, FACTORY

BRAYH SALES OFFICE OR THE, FACTORY AT AURORA, ILLINOIS.

SECTION ~ ITEtl 1

DATED JUNE !%~

INSTRUCTION MANUAL

OPERATION

CENTRIFUGAL PUMP

CENTRIFUGAL PUMP OPERATION. Centrifugal pumps operate under a wide range of conditions.

The pump you have selected exactly fits your spe cific requirements. Before putting your pump into operation however, there are certain basic ground rules that have to be followed to assure maximum efficiency, long pump life, and maintenance free service.

Centrifugal pumps should never be started or run dry. Operating a pump dry can cause burning of the packings or seal, resulting in distruction of the pack ings or seals, and possible scoring of the pump shaft.

To prevent the pump from being run dry, the pump should be primed before starting it.

A centrifugal pump should not be throttled, or the volume controlled on the suction side of the pump.

Throttling the pump on the suction side, not only re duces the capacity, but also reduces pump efficiency, and more important, can cause serious damage to the pump due to cavitation. Cavitation occurs when the pressure at any point inside the pump drops be low the vapor pressure of the liquid. The liquid flashes and forms vapor bubbles. These bubbles move along with the liquid into a higher pressure area, where the bubbles collapse or implode creating an area of low pressure. The implosion phenomenon is characterized by a crackling noise and sometimes by loud knocking as the vapor bubbles are collapsed.

Repetition of this action causes a wearing away of the metal on the impeller and other parts of the pump, and if allowed to continue can result in seri ous damage to the pump.

Pump capacity can be effectively controlled by use of a throttling valve in the discharge piping. Most centrifugal pumps can be operated for brief periods of time with the throttling valve closed without build ing up excessive pressure or overloading the drive unit. In fact, a centrifugal pump operating against a closed discharge line at its rated capacity, actually requires less power to operate than it does when the throttling valve is open.

The pump should never be started with the throttling valve completely closed however because a condition of water hammer could exist. The condition of water hammer is caused by an increase in pressure due to changes in velocity of the liquid flowing through the pipe line. When the velocity is changed by closing a valve or by some other means, the magnitude of the pressure produced is frequently much greater than the static pressure on the line, and may cause rup ture or damage to the pump, piping, or fittings.

Water hammer may be controlled by regulating valve closure, or the use of relief valves and slow closing check valves.

On pumps equipped with packings. there should be sufficient leakage from the packing to insure lubri cation of the packing and effective cooling of the stuffing box. The packing glands should always be adjusted evenly and not too tightly. Over tightening the packing can generate heat which will burn the packing and cause scoring of the shaft. making it necessary to replace both the shaft and the packings.

Adequate precautions should be taken to prevent freezing of liquid in the pump when the pump is not in operation. If there is any possibility of freezing. the water should be drained off by removal of the plugs provided in the pump casing.

All mounting b01ts and pipi~g S<?..r:nections must be firmly tightened to prevent'i:!xceS'sNe vibration, leak age, and possible damage to the pump. The mount ing bolts are particularly important. If they are not firmly tightened, the base plate upon which the pump is mounted may deflect, causing a misalignment of the pump and the driver.

STARTING THE PUMP. In order to start your pump. it will first be necessary to prime it.

PRIMING THE PUMP. Your pump will not operate satisfactorily until it is primed. All air must be

FIGURE 1. PRIMING BY HAND

@ f%8 AUR0AA. PUMP

AURORA• JLL.fNOI~

CENTRIFUGAL PUMP OPERATION

expelled from the suction piptng and pump casing, and replaced by the liquid to be pumped. There are s~veral methods of priming pu~ps. The one you se le,ct :Will depend on your specifi<) requirements.

FLOODED SUCTION PRIMINC. This method of priming a pump is relatively: simple. The liquid source is located above the pump, and all that is ne.cessary to prime the pump Is to open the air vent valve or plug in the pump casing, and to crack the gate valve in the suction line. ; The suction line and pump should be filled slowly until a steady stream of liquid is observed flowing fro~ the air vent. After your pump is operating. it is recommended that the air vent valve or plug be openeid again to insure that all air has been expelled from the pump casing.

DISCHARGE , GATE

lvALYE

FIGURE 2. FLOODED SUCtiON PRIMING

FOOT VALVE PRIMING. A foot valve can be used for priming on suction lift applications. The foot valve located at the bottom end Qr foot of the suction

DISCHARGE

i !

FIGURE 3.j PRIMING WITH A FOOT VALVE

OUTLET

INLETS

FIGURE 4. FOOT VALVE CUTAWAY

piping, functions as a check valve which allows flow in one direction only, toward the pump.

~ ,-i¥.,~:·~,5:~

Initial priming is accomplished by completely filling the suction piping and pump casing with the liquid to be pumped. This can be done by removing the air vent valve or plug at the top of the pump casing, and inserting a pipe nipple in the orifice with 'an appro priate increaser to accommodate a hose connection .

A priming line can also be inserted in the discharge piping between the check valve and the pump, or the priming can be done with a bucket and funnel. The important thing is to completely fill the suction pipe and pump casing with liquid.

When the pump is started, the vacuum created by pumping the priming fluid, combined with atmos pheric pressure in the liquid well, forces liquid into the suction piping, thus opening the valve and keeping it open until the pump is shut down. When the pump is shut down, the liquid being pumped reverses its flow causing the valve to close. The liquid is now trapped in the suction piping and pump casing, thus maintaining a prime on the pump.

VACUUM PRIMING. Vacuum priming consists of re moving air from the pump casing and suction piping, and drawing liquid into them by means of a vacuum creating device. The types of vacuum equipment range from a simple hand pump to complex central priming systems. Your specific priming require ments will govern what type of vacuum primer you use.

AIR EJECTOR. One type of vacuum primer is the air ejector. If liquid under pressure, or steam is available, an ejector can be used. The ejector is connected to the air vent orifice. A stream of the ejecting medium is passed through the ejector cre ating a vacuum in. the ejector, and drawing air from the pump casing and suction piping. When liquid flows steadily from the ejector discharge pipe, the pump is primed.

CENTRIFUGAL PUMP OPERATION

LIQUID

GATE

VALVES

SUPPLY I •.

)l{£

FOOT VALVE

(OPTIONAL)

FIGURE 5. PRIMING BY EJECTOR

AIR

INLET

FROM

PUMP

STEAM AND AIR

DISCHARGE

EAM INLET

FIGURE 6. EJECTOR CUTAWAY

VACUUM PUMPS. Rotary or reciprocating pumps are frequently used as vacuum pumps. They fall into two categories, wet-vacuum and dry-vacuum.

The principle of operation is essentially the same, however, the dry-vacuum pump cannot accommodate a liquid and air mixture, while the wet-vacuum pump can accommodate liquid, air, or a combination of both.

Vacuum pumps can be installed as part of a central priming system servicing many pumps, as an auto-

AIR RELEASE VALVE- fLOAT CONTROLS VALVE WHICH

PERMITS AIR TO PASS, BUT CLOSES WHEN WATER

CHAMBER FILLS .

VACUUM PUMP

SEALING

WATER

AIR DISCHARGE

FIGURE 7. VACUUM PUMP PRIMING

matic prmung system, or as a manually controlled independently driven pump.

The suction piping of the vacuum pump is connected to the air vent orifice on the pump to be primed.

The vacuum pr.oduced by t)l~, V<!£,m~m pump removes air from the turbine pump' suctfori 'piping and casing, and draws liquid from the liquid well into the tur bine pump. Dry-vacuum pumps must be installed so that no liquid is taken into the air pump. Installation of a water trap, or use of a vacuum tank are recom mended for dry vacuum pumps .

INDUCTOR PRIMING. On suction lift applications it may be desirable to prime your pump with a priming

PRIMING

INDUCTOR--~~--*

FIGURE 8. INDUCTOR PRIMING

CENTRIFUGAL PUMP OPERATION

inductor. This type of primer is comprised of a liquid nozzle and an inductor at the foot end of the suction piping. The nozzle and inductor are con nected to a high pressure liquid supply such as a city water service.

The pump is primed by opening the valve in the pressure line. This will allow the liquid to flow through the nozzle and into the inductor. The ve locity of the high pressure liquid drives the liquid into the suction piping and up to the pump, thus com pleting the priming operation.

POSITION OF DISCHARGE GATE VALVE WHEN

STARTING. The discharge gate valve should par tially be closed when a high or medium head cen trifugal pump is started, because this type of pump requires much less power with the gate valve closed, than when it is operated at rated capacity and head with the discharge gate valve open. As soon as the pump is up to operating speed, the discharge gate valve should be opened to the desired position.

POSITION OF SUCTION PIPING GATE VALVE. In flooded suction applications, the gate valve is opened at the time the pump is being primed. and will re main open for starting and operation.

COOLANT VALVES. Valves in the cooling liquid line should be opened prior to the pump's being started, and will remain open while the pump is in operation, unless it is desirable to check the rate of leakage from the stuffing box.

SHUTTING DOWN THE PUMP. To shut down your pump. simply close the discharge gate valve and shut down the motor:. If it is necessary for the pump to maintain its prime while it is shut down, it is ad visable to install either a foot valve or a check valve in the suction piping.

INSTRUCTION MANUAL

TROUBLESHOOTING

CENTRIFUGAL PUMP

Your Aurora Pump has been engineered and care fully selected for your application. It should pro vide years of trouble-free service. However, any piece of machinery is subject to wear and occasional malfunctions.

To help you quickly isolate and rectify any mal function the following troubleshooting chart has been prepared.

Frequent use of the chart to determine the cause of minor operating problems may prevent a major prob lem or possible breakdown of your pump .

@ 1968 AURORA PUMP

AURORA, IL..LINOIS

SECTION 5 ITEM 1

DATED JUNE 1968

TROUBLE

1. Pump fails to prime or loses its prime

2. No discharge from pump

3. Pump does not de-liver rated capacity

4. Insufficient pressure

(i:ENTRIFUGAL PUMP TROUBLESHOOTING

PROBABLE CAUSE REMEDY

a. Air leaks in suction a. Clean and tighten all suction connec-lines tions; relocate suction inlet in liquid source

b. Suction strainer is b. Remove dirt, leaves or other material clogged from strainer.

c. Suction lift is too high c. Re-evaluate pump requirements and correct suction conditions accordingly.

Consult your local Aurora Pump Sales Office.

d. Defective priming valve d. Replace valve.

e. Defective packing or e. Replace packing or seal.

seal

a. Pump is not properly a. Reprime the pump; refer to priming primed troubles and remedies.

b. Total head is too high b. Re-evaluate head calculations; meas-ure elevation differences between pump and liquid source, and pump and discharge point. Consult your local Aurora Pump Sales Office.

'c. Driver is not operating c. Check voltage of electric motor; check at rated speed steam pressure of steam turbine;

check engine R.P.M.'s. Refer to ap-plicable maintenance manuals for

: ;P possible trottbles and corr-ecti'Veo ac-tion.

d. Impeller or discharge d. Back flush pump to clear obstruction;

line is clogged disassemble pump and/or piping and remove obstruction.

':e. Wrong direction of ro- e. Check wiring against diagram on motor tation name plate and in controller; reverse any two power leads on a three-phase motor; replace a single phase motor.

f. Pump is vapor bound f. Provide additional pressure on liquid

' being pumped by elevating liquid source or pressurizing the supply tank.

:a. Pump is not properly a. See 2.a. above.

primed

:,b. Suction lift is too b. See l.c. above.

high

':c. Excessive air in c. See l.a. above.

I liquid 'I d. Air leakage through d. See l.e. above.

stuffing box

le. Driver is not operating e. See 2.c. above.

i at rated speed

lf. Impeller is clogged f. See 2.d. above.

II g. Wearing rings are g. Replace wearing rings.

I ! worn

ih. Impeller is damaged h. Replace impeller.

it. Pump is vapor i. See 2.f. above.

bound

~- Excessive air in liquid a. See 3.c. above.

r· Drive is not operating at b. See 2.c. above.

rated speed f· Wrong direction or ro- c. See 2.e. above.

i tation ~. Total head is too high d. See 2.b. above.

f· Wearing rings are e. See 3.g. above.

I worn

f. Impeller is damaged f. See 3.h. above.

g. Casing gasket is de- g. Replace casing gasket.

i fective allowing inter-nalleakage

~- Liquid is vaporizing h. See 2.f. above.

l l

CENTRIFUGAL PUMP TROUBLESHOOTING

• TROUBLE PROBABLE CAUSE REMEDY

5. Pump starts then a. Air leaks in suction a • See l.a. above.

• stops pumping line

b. Air pocket in suction b. Reprime the pump; elin:iinate air line pocket conditions.

c. Water seal line is c. Remove obstruction trom water line.

plugged ~, ,'', d~

d. Excessive air in d. See l.a. abOVe.

liquid

e. Suction lift too e. See l.c. above.

high

f. Defective packing or f. See l.e. above.

seal

g. Pump is vapor g. See 2.f. above.

bound

6. Excessive power a. Speed is too high a. Internal electric motor wiring is in-consumption correct; replace motor; refer to ap-plicable driver maintenance manuals for possible troubles and corrective action.

b. Wrong direction of b. See 2.e. above.

rotation

c. Total head is too c. See 2.b. above.

high

d. Total'head is too d. Re- elaluate head S'dfidJ.fibns; correct low as required. Consult your local

Aurora Pump Sales Office.

e. Impeller is clogged e. See 2.d. above.

f. Impeller is binding f. Relieve strain on casing; adjust im-peller clearance.

g. Motor shaft is bent or g. Replace motor shaft.

worn

h. Driver and pump are h. Realign driver with pump.

misaligned

i. Power frame shaft is i. Replace shaft.

bent

j. Wearing rings are j. See 3.g. above.

worn

k. Packing is incorrectly k. Install packings correctly; replace if installed necessary.

7. Pump is noisy or has a. Magnetic hum a. Consult motor manufacturer.

excessive vibration b. Motor bearings are b. Replace bearings. .

worn

c. Foreign material in im- c. Remove foreign material.

peller

d. Impeller is binding d. See 6.f. above.

e. Motor shaft is bent or e. See 6.g. above.

worn

f. Driver and pump are f. See 6.h. above.

misaligned

g. Power frame shaft is g. See 6.1. above.

bent

h. Foundation is not rigid h. strengthen foundation; change method of mounting pump unit.

i. Worn bearing in power i. Replace bearing.

frame

j. Impeller is damaged j. See 3.h. above.

k. Lack of lubrication in k. Lubricate power frame bearings; re-power frame place bearings if damaged.

1. Pump is not properly 1. Check levelness of pump.

• leveled

m. Piping is not supported m. Provide support for suction and dis-

. charge piping.

I n. Pump is cavitating n. Re~evaluate pump application; consult I 1 local Aurora Pump Sales Office. f

SECTION 2 ITEM 1

DATED JUNE 1968

INSTRUCTION MANUAL

INSTALLATION

CLOSE COUPLED PUMP

GENERAL. The life of your Aurora pump can be extended considerably by carefully following the in stallation instructions contained herein. Each step of the pump installation instructions plays a vital part in assuring long life, efficient operation, and reduced maintenartce, from the initial location of the pump through prestarting directions.

UNPACKING YOUR PUMP. The crate containing your pump should be opened immediately upon re ceipt from the factory, and the pump generally in spected for damage and shortage of parts. Particular attention should be given to the discharge and suction nozzle threads or flanges. Any damage or shortage of parts should be reported to the carrier immedi-ately. ;'$1 ·

CLEANING. If yo\lr pump is to be installed imme diately, it will be necessary to remove the protective covers from all openings, and to clean the exposed metal parts thoroughly with a cleaning solvent to re move the preservative coating .

STORAGE. If your pump is not to be put in service immediately it should be covered and stored in a clean dry area. ~he protective covers and preser vative should be left intact until the pump is put into service. For exte~ded storage, the pump should be dried internally with hot air or some other suitable means, and once free of moisture, filled with a pro tective fluid such ~s light oil or kerosene. Accord ingly, at time of in~tallation, the pump will have to be completely dismantled and thoroughly cleaned.

PLANNING THE PUMP LOCATION. You probably have spent· considerable time planning where your pump will be located. However you may have over looked some factor which may affect pump operation or efficiency.

The pump should be located as close to the liquid source as possible so that the suction line can be short and direct. ·It should be located in a clean, open area, where it is easily accessible for inspec tion, disassembly and repair. Pumps installed in dark, dirty areas or in cramped locations are often neglected which can result in premature failure of both the pump and the driver.

Your pump should J;>e located so that a hoist or crane can be used to move it Without interference from piping. This factor is often overlooked in the ad vance planning stage.

Protect your pump against the possibility of flooding.

Although water will not seriously damage the pump, the drive motor can be damaged.

HA DISCHARGE PIPING

SUCTION PIPING

FOOT VALVE

FIGURE 1. RECOMMENDED LOCATION

SHORT DIRECT SUCTION

DISCHARGE PIPING

CHECK VALVE

LONG UNSUPPORTED

SUCTION PIPING

STRAINER

FIGURE 2. UNSATISFACTORY LOCATION

LONG INDIRECT SUCTION WITH NO SUPPORT

@ 1961 AURORA PUMP

AURORA• ILLINOIS

CLOSE COUPLED PUMP INSTALLATION

.'he pump should be located in an area where mois ure, either from leakage through the packing or rom condensation, can be adequately drained off.

.Ioisture dripping on exposed metal or wood can atA rapid deterioration of the area. Also, wet to-produce safety hazards.

•dequate provisions should be made for electrical :iring to the pump motor. A switch and overload rotection should be installed near the pump unless t is impractical. The electrical conduit should be ositioned in such a way as to preclude the possibility f moisture entering the conduit or the motor and ausing short circuits.

)utdoor installation will normally provide all of the bove mentioned conditions. However it is advisable J provide a weather shelter for your pump.

'OUNDA TION. The foundation for your pump must e sufficiently rigid to absorb any vibration and tress encountered during pump operation. A raised Jundation of concrete is preferable for most floor nounted pumps. The raised foundation assures a atisfactory base, protects against flooding, simpli tes moisture drainage, and facilitates keeping the rea clean.

our pump should be firmly bolted to the foundation, :h.ether it is a raised concrete base, steelwork wall, r structural member. The mounting bolts or lag crews should be accurately loc~ted per the appli :J.ble Aurora dimension sheet.

BOLT OR

LAG SCREW

THREADED .

INSERT

(J •

PUMP MOTOR

/ BASE

' " " , CONCRETE

FOUNDATION

FIGURE 3. TYPICAL CLOSE COUPLED

PUMP MOUNTING

~ag screws or bolts screwed into threaded inserts n the concrete are recommended for mounting close oupled pumps, rather than studs set into concrete.

'his permits removal of the drive motor without istt.Jrbing the pump liquid end or the piping.

t" a large pump is to be mounted on steelwork or ther structure, adequate support should be provided ) prevent deflection of the structure which could roduce excessive strain on the pump casing and i4t ETTING THE PUM!f. Check the mounting surfaces f the pump unit an~ the foundation to make sure :1ey are clean and free of obstructions.

l

MOUNTING

BOLTS

I

GATE VALVE

DISCHARGE

PIPING

I. ¥ ~·.-·.:~.

FIGURE 4. WALL MOUNTED PuMP' .. ~·:--

Set the pump on the foundation, being careful not to damage the foundation bolts or studs, if used.

Tighten the nuts or bolts finger tight.

LEVELING THE PUMP. Level the pump unit using the suction and discharge nozzles or flanges as ref erence points. Insertion of a short piece of pipe in the threaded nozzles will facilitate use of a spirit level to determine ''whether or not the pump unit is level in all directions. A spirit level also can be used on the machined faces of the suction and dis charge flanges. Insert shims under the mounting feet as required until the pump is level. Firmly tighten the nuts or bolts securing the pump to the foundation.

SHORT PIPE

FIGURE 5. LEVELING PUMP WITH SPIRIT

LEVEL AND SHORT LENGTHS OF PIPE

CLOSE COUPLED PUMP INSTALLATION

r

DISCH~GE SPIRIT LEVEL

~ ~"' e

.~1/ ,.J:l..

~ @ CID

t:::l L-

SUCTION

FIGURE 6. LEVELING WITH SPIRIT

LEVEL ON PUMP FLANGES

PIPING. Your pump unl.t is now ready to be piped.

The piping practices you follow will directly affect the efficiency and power consumption of your pump.

Pay particular attention to the seemingly insignifi cant details involved h1 piping your pumpt,for:: they make the difference between a good and bad installa tion.

SUPPORTING THE PIP~. Both the suction and the discharge piping should be independently supported near the pump. Liber~l use of pipe hangers and support blocks will prevent excessive strain on the pump casing and on the JHpe joints.

SUCTION PIPING. Th£1 suction piping should be short, but no less than :ten pipe diameters in length, and direct with as few e\bows and fittings as possible to keep head loss, from friction, at a minimum.

However, the suction pipe should provide a minimum uninterrupted length, equal to ten pipe diameters, to the pump suction flange. A horizontal suction line should have a gradual ; rise to the pump, and pass under any interfering pi~ing.

LONG

RADIUS

ELBOW

FIGURE 8. RECOMMENDED SUCTION

LIFT PIPING - SHORT AND DIRECT

GATE

VALVE

PIPE SUPPORT

FIGURE 9. RECOMMENDED FLOODED

SUCTION PIPING - SHORT AND DIRECT

DISCHARGE

TANK

FIGURE 7. SUPPORTING PIPING

PIPE. The suction pipe diameter should be at least the same diameter as the suction nozzle on the pump, and preferably larger. Use of a smaller .eter pipe will result in loss of head due to ion. All joints must be tight to maintain prime o e pump.

DISCHARGE

LONG UNSUPPORTED

PIPING

FIGURE 10. UNSATISFACTORY SUCTION LIFT

PIPING - LONG AND INDIRECT WITH NO SUPPORT

SUCTION

FIGURE 11. UNSATISFACTORY FLOODED

SUCTION PIPING - LONG AND INDIRECT

WITH NO SUPPORT

ELBOWS. Long radius elbows should be used in place of standard elbows wherever possible, be cause of their superior flow characteristics. For instance, head loss: in a standard four inch elbow is equivalent to the head loss in a piece of pipe 11 feet long, while the head loss in a long radius elbow is approximately half as much. Elbows should not be at the suction nozzle, but if it is unavoidable, should be installed in a.. vertical position. Elbows installed in any position at the suction nozzle have a tendency to distri"ute the liquid unevenly in the impeller chamber, !causing a reduction in capacity, and creating an und~rsirable thrust condition, THE FRICTION LOSS. IN A LONG RADIUS

ELBOW IS APPROXIMATELY ONE-HALF

THE FRICTION LOSS OF A SHORT RADIUS

ELBOW.

FIGURE 12. LONG VERSUS SHORT

RADIUS ELBOWS

SUCTION

INCORRECT .L

SUCTION

CORRECT

FIGURE 13. ELBOW INSTALLATION ON

SUCTION NOZZLE

REDUCERS. Eccentric reducers should be installed directly at the suction nozzle, with the taper at the bottom to prevent air pockets from forming. Straight taper reducers should never be used in a horizontal suction line because of the air pocket that is formed at the leg of the reducer and the pipe.

INCORREi9T I I

~ I I.

PUMP I "

SUCTION .

SPACER BETWEEN SUCTION AND ELBOW PERMITS

EQUAL FLOW OF WATER TO EACH SIDE OF DOUBLE

SUCTION IMPELLER, PREVENTS EXCESSIVE THRUST

AND RESULTING WEAR ON BEARINGS, ETC.

FIGURE 14. REDUCER BETWEEN ELBOW

AND PUMP SUCTION NOZZLE

'I • _.; .... ',, ·•[ l.

. L'

CLOSE COUPLED PUMP INSTALLATION

SPEC.IAL SUCTION PIPING SPECIFICATIONS FOR HORIZONTAL DOUBLE SUCTION PUMPS

CORRECT

If elbow is necessary. it should be of the long ra dius type.

Discharge piping and suction piping should be supported close to the pump flange to prevent vibration andtStrain on pump casing.

PATH OF

WATER

DISTANCE EQUAL

TWICE DIAMETER

OF INLET PIPE

LESS DESIRABLE

The suction pipe on horizontal double suction pumps. shoUld not be installed so that there is an elbow close to the suction nozzle unless the elbow is mounted vertically. There is always an unevj'ln flow of liquid ·through an elbow and when the elbow is installed at any angle other than vertical more water will enter one side of the impeller than enters the other side. This causes a reduction in capacity and efficiency and creates an axial thrust load which may over heat and possibly cause rapid wear of the thrust bearing.

FIGURE 15

SPECIAL SUCTION PIPING SPECIFICATIONS FOR VERTICAL DOUBLE SUCTION PUMPS

CORRECT INCORRECT

DISTANCE EQUAL

TWICE DIAMETER

OF INLET PIPE

LESS DESIRABLE

Suction connections for vertical mounted double suction· pumps should be installed the op posite of horizontal pumps. That is. if an elbow is installed close to the suction nozzle it should ohly be mounted horizontally. Any angle other than horizontal will cause more water to enter !one side of the impeller than enters the other side. This causes a reduction inca pacity and efficiency and creates an axial thrust load which may over heat and possibly cause rapid wear of the thrust bearing.

FIGURE 16

TYPICAL PIPING FOR DOUBLE SUCTION PUMPS

ELBOW

CORRECT

F1GURE 17. INSTALLATION OF TAPERED

REDUCERS

II----SUCTION

F1GURE 18. RECOMMENDED DISCHARGE

PIPING • SHORT AND DIRECT

GATE VALVE

DISCHARGE PIPING. Discharge piping should also be short and direct as possible, with few elbows and·· fittings, to reduce head loss from friction.

PIPE. The discharge pipe diameter should be the same as, or larger than, the discharge nozzle diam eter. The size of discharge pipe to be used is dependent upon the application. The recommended pipe diameter can be obtained from your nearest Aurora Pump Sales Office.

ELBOWS. Long radius elbows should be used in the discharge piping as well as in the suction piping, to prevent excessive head loss due to friction. When ever possible, elbows should not be installed directly at the discharge nozzle as the turbulence created by the elbow will affect pressure gauge readings.

REDUCERS AND INCREASERS. An increaser should be installed at the discharge nozzle if larger diameter discharge piping is used. Straight taper increasers and/or reducers are satisfactory in discharge piping, because air pockets on the discharge side do not

Jaffect pump efficiency.

ECCENTRIC TAPE RED

REDUCER

INCREASER

F1GURE 20. REDUCER INCREASER INSTALLATION

DISCHARGE

PIPING

F1GURE 19. UNSATISFACTORY DISCHARGE PIPING- LONG WITH EXCESSIVE ELBOWS AND JOINTS

CLOSE COUPLED PUMP INSTALLATION

EXPANSION JOINTS. Expansion joints are used pri marily to prevent tra~smission of piping strain, caused by thermal expahsion and contraction, piping misalignment, pressure i changes, or other causes, to the pump casing. They~ are also used to suppress any noise that may be tr~smitted through the piping.

It is recommended that the flexible metal type of expansion joint be useq because rubber expansion joints, while costing les$, have a tendency to dete riorate, making frequeht replacement necessary.

BELLOWS TYPE

EXPANSION

JOINT

SUCTION

F1GURE 21. EXPANSION JOINT IN SUCTION LINE

FIGURE 22. EXPANSION JOINT IN

DISCHAROE PIPING

I

If an expansion joint mllst be used, an anchor or restraining device shoulq be installed between the joint and the pump to p~event objectionable forces from being transmitted ~o the pump. If an anchor is not installed at this point, a force equal to the area of the expansion joint times the pressure in the pipe is developed and tr~smitted to the pump. This force may exceed the al~owable flange loading and could result in damage i to the pump or piping.

PIPE ALIGNMENT. Prop~r piping alignment is es sential before connectiorj. is made. Piping align ment should never be a<jhieved by force, as this could produce strain on ithe piping and the pump casing. Proper supports ~hould be installed for the piping to keep its weight off the pump casing .

When flange bolts are used, line up the piping first, then lOO!Sely install flange bolts. Check the piping alignmerit; and tighten the' flange bolts until all bolts are tight~ned securely.

MISALIGNMENT'-.,._ FLANGE

----"fit BOLTS :

FLANGE

BOLTS

INCORRECT.··

PROPER NATURAL

ALIGNMENT

F1GURE 23. PIPE ALIGNMENT

AIR IN PIPING. One of the most common conditions affecting pump efficiency is the formation of air pockets in the suction line. The air pockets are a result of high points and improper installation of elbows. reducers, and valves in the suction piping.

For suction lift applications, lantern rings are re quired to prevept air from,, ~~1;1g into the pump through the stuffing box. · · .. :.-

The pump seals or packings depend on the liquid being pumped for lubrication. Excessive air can prevent proper lubrication with resultant damage to them .

In suction lift applications, the suction pipe in the liquid well must be sufficiently submerged to prevent exposure of the end of the pipe when the well is at its minimum level and to prevent vortexing action (whirlpool effect) of the liquid at the suction pipe, which will draw air into the pipe. Also, care should be taken to keep the suction pipe located away from the well inlet since the incoming liquid may be carrying air bubbles. Another cause of air in the liquid is dropping of the liquid from too high a point into the well.

DISCHARGE AIR POCKET

+_SUCTION

F1GURE 24. AIR POCKET IN REDUCER

fl

7 .!

i

FIGURE 25. AIR POCKET IN ELBOW

I" AIR POCKET

INCORRECT

CORRECT

FIGURE 26. AIR POCKET IN HORIZONTAL

SUCTION PIPING

VALVES. Valves are an important part of your in stallation, for they facilitate priming of the pump, and control the volume of the pumped liquid.

INLET PORTS

FIGURE 27. FOOT VALVE

SUCTION LIFT. In suction lift applications where the suction lift is low a foot valve can be installed to maintain the prime on the pump. A foot valve i~ essentially a check valve, aUowing now in one direc tion only, toward the pump. When the pump is shut down, the pressure of the liquid returning to the well, causes the valve to close, retaining the liquid in the suction line.

A slow closing check valve should be installed when the static discharge head is high. A foot valve should not be used under these conditions, as failure of the driver would allow the water to rush back rapidly thus causing a heavy water hammer.

Foot valves, when used, should be of the flat type rather than multiple spring type. The valve should have a large. inlet area, because the friction loss in a foot valve is high. Install check and foot valves as indicated by arrow to ensure proper installation.

FIGURE 28. FOOT VALVE INSTALLED

WITH SCREEN

FLOODED SUCTION. When the liquid source is above the pump centerline, a flooded suction condition exists, and a gate valve is required to shut off the liquid supply for pump inspection and maintenance.

The gate valve should be installed with the stem in a horizontal or downward position to prevent forma tion of an air pocket in the valve.

DISCHARGE VALVES. The discharge piping should include a check valve and a gate valve. The check

FIGURE 29. GATE VALVE AND CHECK VALVE

CLOSE COUPLED PUMP INSTALLATION

valve should be locat~d bet:veen the_ gate v~lve and 'the pump. If an incre~ser IS used m the d1scharge piping, the increaser should be installed between the pump nozzle and the qheck valve. The check valve protects against a reyerse flow of the liquid if the driver fails.

The gate valve is use~ in the priming operation, as a throttling valve to :control pump volume, and to shut down the pump fdr inspection and maintenance.

AIR VENT VALVE. Vent valves are installed at the high points in the pump casing to allow air or vapor to escape. These valves are used to release trapped air from the pump ca~ing during priming and when pump becomes air bound.

/DISCHARGE

c:=~

PLUG

FlGURE 30. AIR ~ENT VALVE OR PLUG

STRAINERS AND SCREENS. It is important to remove foreign matter; that can clog the pump and impair its capacity, or stop it completely. Small particles such as sand,'; dirt, scale from inside pipe and other extraneous mlj.terials can get into the close clearance parts of the pump and cause considerable damage to the parts. ·

' Strainers should be selected so as to have a total area of holes equal to at least four times the suction pipe area. 1

In applications where s~icks, twigs, leaves and other large debris are pres~nt, a larger outside screen should be placed aroun9 the suction inlet to prevent choking of the straineJ:j. This screen should have sufficient openings so that flow velocity does not exceed two feet per secord.

i

PRIMING THE PUMP. iYour pump will not operate satisfactorily until it i~ primed. All air must be expelled from the suct~on piping and pump casing, and replaced by the liq4id to be pumped. There are several methods of prilming pumps. The one you select will depend on your specific reqUirements.

I

FLOODED SUCTION ~RIMING. This method of priming a pump is re~atively simple. The liqUid source is located above the pump, and all that is necessary to prime the iPump is to open the air vent

AIR VENT VALVE

OPENING

SUCTION

FlGURE 31. PRIMING BY HAND valve or plug in the pump casing, and to crack t~e gate valve in the suction line. The suction line and pump should be filled slowly until a steady stream oa liquid is observed flowing from the air vent. MteWJ your pump is operating, it is recommended that the air vent valve or plug be opened again to insure that all air has been expelled from the pump casing.

FOOT VALVE PRIMING. A foot valve can be used for priming on suction lift applications. The foot valve, located at the bottom end or foot of the suc tion piping; functions as a check valve which allows flow in one direction only, toward the pump.

Initial priming is accomplished by completely filling the suction piping and pump casing with the liqUid to be pumped. This can be done by removing the air vent valve or plug at the top of the pump casing and inserting a pipe nipple in the orifice, with an appro priate increaser to accommodate a hose connection.

A priming line can also be inserted in the discharge piping between the check valve and the pump or the priming can be done with a bucket and funnel. The important thing is to completely fill the suction pipe and pump casing with liquid.

When the pump is started, the vacuum created by pumping the priming fluid, combined with atmos pheric pressure in the liquid well, forces liquid into the suction piping, thus opening the valve and keeping it open until the pump is shut down. When the pump is shut down, the liquid being pumped reverses its flow, causing the valve to close, trapping the liquidA in the suction piping and pump casing, thus main-"W taining a prime on the pump.

VACUUM PRIMING. Vacuum pr1mmg consists of remoVing air from the pump casing and suction piping and drawing liquid into them by means of a vacuum creating device. The types of vacuum equip ment range from a simple hand pump to complex cP.al priming systems. Your specific priming r . · ·ements will govern what type of vacuum pn er you use.

EJEC

(OPTIONAL)

FOOT VALVE

FIGURE 32. PRIMING BY EJECTOR

AIR EJECTOR. One type of vacuum primer is the air ejector. If liquid under pressure or steam is available, an ejector can be used. The ejector is

c. -cted to the air vent orifice. A stream of the e~g medium is passed through the ejector creat mg a vacuum in the ejector, and drawing air from the pump casing and suction piping. When liquid flows steadily from the ejector discharge pipe, the pump is primed.

AIR

INTAKE

STEAM AND AIR

DISCHARGE

STEAM

ENTRANCE

FIGURE 33. EJECTOR CUTAWAY

VACUUM PUMPS. Rotary or reciprocating pumps are frequently used as vacuum pumps. They fall into two categories, wet-vacuum and dry-vacuum.

. The principle of operation is essentially the same, however, the dry-vacuum pump cannot accommodate a liquid and air mixture while the wet-vacuum pump can accommodate liquid, air or a combination ofboth.

Vacuum pumps can be installed as part of a central priming system servicing many pumps, as an auto matic priming system, or as a manually controlled independently driven pump.

The suction piping of the vacuum pump is connected to the air vent orifice on the pump to be primed.