HB-243_(FRV40-225-099-010)_Marine_Shaft_Braking_System.pdf

FRV40-225-099-010

DESCRIPTION, OPERATION, INSTALLATION AND

MAINTENANCE INSTRUCTIONS

Marine Shaft Braking System Model: Twiflex

T40-EN Caliper(s) With 20:1 Air/Hydraulic Intensifier

Halter Marine, Inc.

13085 Seaway Rd.

P.O. Box 3029 Gulfport, MS 39505

50-SPNA-1-00031

PUBLISHED BY DIRECTION OF NOAA

FRV40-225-099-010

DESCRIPTION, OPERATION, INSTALLATION AND

MAINTENANCE INSTRUCTIONS

Model: Twiflex

T40-EN Caliper(s) With 20:1 Air/Hydraulic Intensifier

13085 Seaway Rd.

P.O. Box 3029 Gulfport, MS 39505

PUBLISHED BY DIRECTION OF NOAA

27 SEP 2005

RECORD OF CHANGES

Change No.

Date Title and/or Brief Description Signature of Validating Officer

APPROVAL AND PROCUREMENT RECORD PAGE

APPROVAL DATA FOR: FRV40-225-099-010

TITLE OF MANUAL: Marine Shaft Braking System

APPROVAL AUTHORITY: NOAA

Contract Number

Ship Applicability

Qty Of Manuals

Building Yard

50-SPNA-1-00031 FRV40-225 2 EA Halter Marine Inc.

REMARKS:

CERTIFICATION: It is hereby certified that FRV40-225-099-010 to be provided under contract 50-SPNA- 1-00031 has been approved by the approval data shown above.

Date:________________ Chand, LLC Mathews, LA 70375

CAGE CODE: 0D5X4

VALIDATION PERFORMANCE

Title of Publication

Contractor Sub-Contractor (If

Performing Validation)

Contract No.(s) and Purchase Orders, If Applicable

Chapter

Section Paragraph Date Validation Completed

Check here if Not Validated

Contents of this manual have been validated and certified to be applicable to the equipment furnished under the above procurement as specified for Validation.

Name & Authority of Validating Officer: Signature of Validating Officer:

FOREWORD

This manual is intended to clearly and accurately reflect the actual configuration of the installed equipment described for the FRV40-225 Marine Shaft Braking System. Users are urged to report instances noted wherein the manual does not achieve this objective.

This technical manual provides the instructions necessary to operate, to perform maintenance on and troubleshooting of the Marine Shaft Braking System. The text is broken down as follows:

Section 1- Marine Shaft Braking System Model: Twiflex T40-EN Caliper(s) With 20:1 Air/Hydraulic Intensifier

Section 1- Marine Shaft Braking System Model: Twiflex T40-EN Caliper(s) With 20:1 Air/Hydraulic Intensifier

TWIFLEX

MARINE SHAFT BRAKING SYSTEM

T40-EN CALIPER(S) WITH 20:1

AIR/HYDRAULIC INTENSIFIER

INSTALLATION, OPERATION

AND MAINTENANCE INSTRUCTIONS

MANUAL

M1344

(i)

AMENDMENT AND REVISION RECORD - M1344

AMENDMENT NUMBER

ISSUE AND DATE

SIGNATURE AND DATE

WHEN AMENDMENT ISSUED

(ii)

LIST OF CURRENT PAGES - M1344

Page Issue Date

1 1 April 2002

2 1 April 2002

3 1 April 2002

4 1 April 2002

5 1 April 2002

6 1 April 2002

7 1 April 2002

8 1 April 2002

9 1 April 2002

10 1 April 2002

11 1 April 2002

12 1 April 2002

(iii)

INDEX PAGE

1 INTRODUCTION 1

2 GENERAL LAYOUT 1

2.1 Brake Disc 1

2.2 Brake Caliper 1

2.2.1 Technical Data 1

2.2.2 Braking Force 3

2.3 Intensifier 3

2.3.1 Technical Data 3

3 INSTALLATION AND OPERATION 4

3.1 Brake Caliper 4

3.1.1 Mounting 4

3.1.2 Installation 4

3.1.3 Hydraulics 5

3.1.4 Initial Operation 6

3.1.5 Bedding – In 6

3.2 Intensifier 7

3.2.1 Installation 7

3.2.2 Pipe Connections 7

3.2.3 Filling Hydraulic Circuit 7

4 ROUTINE MAINTENANCE 8

4.1 Brake Caliper 8

4.1.1 General 8

4.1.2 Brake Pad Replacement 8

4.2 Intensifier 8

4.2.1 General 8

4.2.2 Initial Checks 8

4.2.3 Monthly Inspection 9

5 MAJOR OVERHAUL AND SERVICING 9

5.1 Brake Caliper 9

5.2 Intensifier 11

5.2.1 Major Overhaul 11

6 FAULT DIAGNOSIS 11

6.1 Low Hydraulic Pressure 11

6.2 Contaminants 11

6.3 Excessive Friction 11

(iv)

7 SPARES 12

7.1 Caliper 12

7.2 Intensifier 12

APPENDIX A

D-A461 Brake Assembly 30” Disc W/2 Calipers D-A458 Brake Assembly 36” Disc W/2 Calipers D-A459 Brake Assembly 36” Disc W/3 Calipers D-A460 Brake Assembly 36” Disc W/4 Calipers D-A462 Brake Assembly 42” Disc W/4 Calipers D-A463 Brake Assembly 48” Disc W/4 Calipers

APPENDIX B

A13033 20:1 Intensifier Assembly Z407/1 20:1 Intensifier Schedule

April 2002

1. INTRODUCTION

Manual M1344 covers the installation, operating and maintenance instructions for the following Shaft Braking systems :-

DISC

DIA.

(in)

DISC

DIA

(mm)

TWIFLEX

CALIPER

QTY. TORQUE

(Nm)

TORQUE

(lbf. In)

HYDRAULIC

PRESSURE

bar (psi)

APPENDIX

REF.

30 762 T40 EN 2 33264 294632 108 (1566) D-A461

36 914 T40 EN 2 40788 361275 108 (1566) D-A458

36 914 T40 EN 3 61182 541913 108 (1566) D-A459

36 914 T40 EN 4 81576 722551 108 (1566) D-A460

42 1067 T40 EN 4 96722 856705 109 (1581) D-A462

48 1219 T40 EN 4 111771 990000 110 (1595) D-A463

TABLE 1

Details of each installation is covered in Appendix A under the reference shown.

The T40 EN brake caliper is a hydraulically applied split caliper design and is adaptable for use on a wide range of brake disc thicknesses from 20mm. For the Shaft Braking systems specified above, the brake disc is nominally 35mm thick (1.375”).

The system comprises two brake pedestals which are positioned opposite each other and mounted on either side of the shaft.

The pedestals are manufactured from 25mm (1”) thick steel plate and to mount the calipers a 5mm (3/16”) thick steel spacer plate is fitted each side of the pedestal to give an overall mounting thickness of 35mm (1 3/16”) i.e. the same thickness as the brake disc.

An air/oil intensifier unit provides the hydraulic pressure necessary to operate the brake calipers.

It comprises a hydraulic master cylinder directly coupled to a spring return air diaphragm chamber. The master cylinder, fed from a reservoir, provides the necessary hydraulic pressure at a ratio of approximately 20:1 from air pressure applied to the diaphragm.

The maximum working air pressure for the Shaft Braking Systems specified above is 5.5 bar (80 psi), see Para. 3.1.4.

2 GENERAL LAYOUT

2.1 BRAKE DISC

The brake disc is supplied pilot bored to be finished machined by the installer.

2.2 BRAKE CALIPER

2.2.1 Technical Data

Caliper Type – T40 EN Twiflex Part No. - 6781342

Material – Spherical graphite BS2789 Grade 420/12 Finish – Electroless nickel plate.

Total caliper mass (2 caliper halves only) –19.6 kg (43.2 lb) (excluding brkt & bolts).

Mass of two bolts (M24 x 220) and two nuts (M24) – 1.9 kg (4.2 lb)

April 2002

Pad dimensions : new pads – 85 x 85 x 19mm (3.35” x 3.35” x 0.75”) Pad wear allowance – 10mm (0.4”).

Total pad friction area – 144cm2 (22.4 in2) Maximum pad retraction – 1mm (0.04”) total Total oil displacement volume per 1mm stroke – 15ml (for two caliper halves).

Hydraulic fluids – use with MINERAL OIL BASED hydraulic fluids i.e.

Shell Tellus 37, Castrol Hyspin AWS32 or SAE equivalent.

Initial oil filling varying from 185ml (pads new) to 300ml (fully worn pads).

FIGURE 1 T40 EN BRAKE CALIPER

PEDESTAL WITH

SPACER PLATES

FITTED EACH SIDE.

35 mm (1.375”)

THK. DISC

April 2002

2.2.2 Braking force.

Maximum working pressure 110 bar = 49.5 kN braking force.

Braking force is defined as the Tangential Force acting on the brake disc at the Effective Disc Radius.

Braking Torque (Nm) = Braking Force (N) x Effective Disc Radius (m) Where Effective Brake Radius = Actual Radius – 0.045

These are typical performance figures for fully bedded and conditioned brake pads. For bedding-in and conditioning see Para.3.1.5.

2.3 INTENSIFIER

2.3.1 Technical Data

Twiflex Part No. 8400247 Twiflex Drg. A13033

Details of the Intensifier assembly are included in Appendix B.

0 5 10 15 20 25 30 35 40

Braking Torque - kNm

O il

P re ss u re b ar

Disc Diameter mm 610 760 915 1065 1220 1370 18301525

April 2002

3 INSTALLATION AND OPERATION

3.1 BRAKE CALIPER

3.1.1 Mounting

The T40 EN calipers are factory mounted to the brake pedestal and the two M24 x 220 long mounting bolts which are required for a disc thickness of 35mm (1.375”) are tightened to a torque of 680 Nm (500lbf.ft).

(Note:-These bolts are grade 8.8 minimum and the nut is grade 8).

See FIG 1 and Appendix A for mounting details.

All hydraulic piping and the manifold on each caliper / pedestal assembly is factory fitted and is designed to clamp onto the disc during installation by activating the calipers using an air supply (100 to 150 psi ) which should be available on site. (see Para. 3.1.2)

Each pedestal is drilled by the installer with holes to accommodate 7/8” x 3.25” long Grade 8 mounting bolts. These bolts are supplied by the installer and are used to mount the brake pedestal to the installers mounting bracket. see Appendix A.

3.1.2 Installation

The caliper / pedestal assembly is installed in 2 stages as follows:-

STAGE 1

(i) Position the caliper / pedestal assembly over the disc. The correct position of the caliper and required braking path is shown in FIG 1.

Note: The pedestal(s) with spacer plates is 35mm ( 1 3/16”) thick, the same as the disc thickness.

It is important to ensure the caliper / pedestal assembly is positioned in line with the disc so that the brake pads are presented squarely to the disc face.

(ii) Connect the air line from the air supply (available on site) to the manifold (in place of the hydraulic connection to the Intensifier) and switch on the air supply to activate the calipers. This will ensure the caliper is held in correct alignment.

The caliper / pedestal is now in position to locate the installers mounting bracket. This will support the assembly to the reduction gear foundation.

(Note: steel plate used for the mounting bracket should be 19mm (0.75”) thick minimum)

April 2002

STAGE 2

The recommended installation method is to use a resin pour to ensure correct alignment between the caliper / pedestal assembly and the installers mounting bracket as follows:-

(iv) Weld the mounting bracket to the engine/gear foundation allowing approximately 13mm (0.5”) between the caliper / pedestal assembly and the mounting bracket.

See Appendix A.

(v) Mark hole locations and drill the 7/8” holes in the mounting bracket

(vi) Install 7/8” x 3.25” long SAE Grade 8 bolts through the mounting bracket and caliper / pedestal assembly coating them with parting agent and make the resin pour.

(vii) Refer to the resin manufacturers recommendations for the pouring procedure.

See Appendix A for the minimum resin chock areas for each Shaft Braking System.

NOTE: Air pressure on the calipers must be maintained until the resin has cured.

(viii) After the resin has cured in accordance with manufacturers recommendations, dry torque the mounting bolts to 395 Nm (290 lbf.ft). See Appendix A.

(ix) Switch off the air supply and remove the air line from the manifold on the caliper / pedestal assembly.

(x) Remove any plugs or fillings and connect the hydraulics as detailed in Para 3.1.3 to the caliper / pedestal assembly.

3.1.3 Hydraulics

The caliper / pedestal assembly is factory fitted with a manifold and all hydraulic piping.

Ensure that the pipework is supported securely, connect the hydraulic pipe from the Intensifier to the manifold on the caliper / pedestal assembly.

(Note: Manifold connection : straight connector 3/4 -20 SAE x 7/16-20 37° JIC M

See Appendix A for details of connections.

Instructions for ‘Filling the Hydraulic Circuit’ are detailed in Para 3.2.3.

April 2002

3.1.4 Initial Operation

Fully pressurise the caliper depending on the brake system specified as follows:-

APPENDIX

REF.

AIR SUPPLY PRESSURE

bar (psi)

HYDRAULIC (CALIPER) PRESSURE

bar (psi)

D-A461 5.40 (78) 108 (1566) D-A458 5.40 (78) 108 (1566) D-A459 5.40 (78) 108 (1566) D-A460 5.40 (78) 108 (1566) D-A462 5.45 (79) 109 (1581) D-A463 5.50 (80) 110 (1595)

TABLE 2

Inspect all connections and joints for leaks.

Ensure that clamping has taken place on the brake disc and that brake pads are flat and square on the brake disc.

Release hydraulic pressure and observe that pressure collapse is rapid and that each brake pad retracts from the brake disc by approximately 0.5 mm.

Note: The T40 EN caliper incorporates special seals which automatically retract the brake pads by 1mm when the brakes are released.

Operate the caliper several times checking for correct operation and leaks. Leave the caliper installation clean and dry.

NOTE: Full brake performance will not be realised until the pads have been bedded in and conditioned, see Para 3.1.5.

3.1.5 Bedding - In

This is to ensure the pads are bedded onto the disc so that the full area of pad is making contact and the disc surface itself is beginning to polish. In addition it is important to progressively generate more heat at the pad surface to condition the material by causing chemical changes until the pads are able to perform to their maximum duty.

The principle for dynamic braking is to work the brake lightly at first to remove pad high spots and therefore achieve around 100% pad contact with the disc.

Progressively heavier braking can then be applied until full rated duty is achieved.

If there are signs of distress such as the deposition of pad material on the disc, it is suggested that the brake is worked more slowly towards the braking duty.

This may involve gradual increases in both rubbing speed and / or pad pressure as appropriate to the installation.

Monitor the disc temperature during bedding – in and allow adequate cooling time to prevent excessive temperatures occurring. A safe peak braking path temperature is 250°C.

April 2002

3.2 INTENSIFIER

3.2.1 Installation

The Intensifier should be mounted as shown in Appendix B. The unit should be level or higher than the manifold on the caliper / pedestal assembly. See Appendix A.

It is also desirable to protect the unit as far as is possible from excessive heat, vibration and mechanical damage. Hydraulic pipe runs should be kept as short as possible, particularly if the maximum number of calipers is being operated. The reliability of the air supply is also important and it must be remembered that fluctuations in air pressure will cause corresponding fluctuations in the braking force.

Note: A maximum of four calipers per master cylinder can be used with this Intensifier

3.2.2 Pipe Connections

Air and hydraulic connections are illustrated in Appendix A. Cleanliness and careful assembly are essential to ensure air and fluid tight joints and to avoid trouble due to the presence of foreign matter. Hematite or similar sealant will be found helpful in ensuring an air tight connection between the adaptor and the air cylinder body.

3.2.3 Filling Hydraulic Circuit

It is important to bleed air from the brake system before use. This is best accomplished by engaging the brake using a low pressure air supply as follows:-

(i) Set the air supply pressure to between 1 and 1.4 bar (15 and 20 psi)

(ii) Fill the reservoir (see Appendix B) with mineral oil based hydraulic fluid such as Shell Tellus 37, Castrol Hyspin AWS32 or SAE equivalent.

(iii) Starting on the caliper with the shortest pipe run to the master cylinder, wipe the bleed screw clean and attach one end of a suitable rubber or plastic tube immersing the open end in a small quantity of brake fluid contained in a clean glass jar.

(iv) Apply air pressure to the intensifier as detailed in (i).

(v) Slacken bleed screw to allow fluid to flow into the jar until the fluid flow ceases.

(vi) Close bleed screw.

(vii) Exhaust the air allowing the master cylinder piston to return.

(viii) Repeat operations (iii) and (vii) until fluid passing into the jar is completely free from air bubbles, then retighten bleed screw.

(ix) Repeat bleeding operation for each caliper in turn. Check the oil level in the reservoir during these operations and top up as necessary. If the reservoir is inadvertently emptied the whole operation will have to be repeated.

April 2002

(ix) Finally fill reservoir to within 12mm (0.5”) of the top, replace cap, clean up generally and test for oil leaks with full air pressure maintained for 2/3 minutes. The oil volume of the reservoir is 470 cm2 maximum and 300 cm2 minimum.

Note: the oil level should always show ‘full’ on the level gauge. See Appendix B.

(x) Adjust the air supply to the working pressure as stated in TABLE 2.

4 ROUTINE MAINTENANCE

4.1 BRAKE CALIPER

4.1.1 General

Very little routine maintenance is required. Ensure that the brake pads and disc are kept free of oil and grease; replace pads if they become contaminated. The brake disc must be kept clean, and build-up of dust or other deposits removed periodically from the caliper.

The level and cleanliness of hydraulic fluid in the system should also be monitored periodically; contaminated fluid should be replaced and the whole system flushed through with clean fluid. (see Para 3.2.3)

4.1.2 Brake pad replacement

Item numbers in brackets refer to FIG. 2

Brake Pad replacement is carried out with the brakes released.

In most cases, brake pads can easily be changed without removing the brake caliper.

However in some instances it may be necessary to remove the caliper from the pedestal as detailed in Para. 3.1.1.

It is suggested that the hydraulic piping is left connected but removed from the pipe clamps to free the assembly and give access for pad removal.

Pad replacement is carried out from the rear of the caliper. With the brake off, the worn pads may be removed after unscrewing the pad retaining screws (7) and removing the pad retaining plates (3).

Re-assembly of the new replacement pads follows the reverse of this procedure, but note that the mating surfaces are clean and that the slotted pad backing plate is located around the keep button on the piston. The pads should slide easily into position.

4.2 INTENSIFIER

4.2.1 General

The frequency of routine maintenance requirements will depend on use and working conditions, and will become clear with experience.

4.2.2 Initial Checks

After the first week of operation, check security of all connections and joints. Inspect oil level and check for leaks.

April 2002

4.2.3 Monthly Inspection

Carry out a visual inspection of the system, including pipework. Check reservoir oil level.

If sudden losses occur, locate leak and remedy.

NOTE. It is also important to ensure that the reservoir is full, to ensure that sufficient oil is supplied to operate the maximum number of brakes with fully worn pads.

5 MAJOR OVERHAUL AND SERVICING

5.1 BRAKE CALIPER

Each half of the caliper has only one moving part, the servicing procedure in the event of leakage consists merely of disassembly and inspection, followed by replacement of seals, and the piston if necessary. See FIG. 2

Before disconnecting the hydraulic pipes, the caliper should be cleaned, especially in the areas around the hydraulic connection and bleed screws.

Disconnect hydraulic pipes, controlling any spillage, and remove caliper from its mounting.

Transfer caliper to the bench, and clean externally before dismantling.

The piston, ITEM 2, can either be pulled out using the pad retention button, or blown out using compressed air at the hydraulic input port.

WARNING: USE LOW PRESSURE AIR ONLY (3 bar (40 psi)) AND FOR SAFETY

PURPOSES BLOW PISTON INTO HAND HELD CLOTH.

The piston should be replaced if the sealing surface is damaged.

The front seal, ITEM 6, which acts basically as a wiper, is an O-ring and thus easily removed.

The main seal, ITEM 5, is a two part type consisting of a split P.T.F.E. backing ring and a rubber sealing element. The backing ring must be removed first. Take care not to damage the groove surfaces when removing the seals.

New seals are easily fitted without tools, but it is important to fit the parts of the main seal in their correct orientations. In particular the backing ring has one radiused edge only, and the split joint must lie flat after fitting. Cleanliness is vital.

Before re-inserting the piston, lubricate the seals and piston lightly with clean hydraulic fluid or a soft compatible grease.

April 2002

Item Component Qty. Item Component Qty.

1 Caliper Body 2 5 Seal 2 2 Piston 2 6 O-Ring 2 3 Pad retaining plate 2 7 Pad retaining screw 2 4 Bleed screw 1 8 Pad assembly 2

FIGURE 2 T40 EN CALIPER PART DETAILS

April 2002

5.2 INTENSIFIER

5.2.1 Major Overhaul

Tests indicate a typical life for the master cylinder seals to be in excess of one million operations.

For preventive maintenance it is suggested that a complete set of replacement seals be fitted at 750,000 operations.

Instructions for removing and fitting seals are available from Twiflex on request.

The spares kit is detailed in Para7.2.

See Appendix B for details of the Intensifier assembly.

It is suggested at the same time the air cylinder diaphragm should also be replaced.

6 FAULT DIAGNOSIS

6.1 Low hydraulic pressure

(i) check pressure.

(ii) re-adjust or rectify supply unit.

6.2 Contaminants on surface of brake pads and disc, especially lubricants

(i) Remove source of contamination.

(ii) Clean brake disc thoroughly.

(iii) Fit new brake pads (see Para. 4.1.2).

6.3 Excessive friction in the caliper, due to corrosion or damage

(i) Dismantle caliper (see Para 5.1).

(ii) Ascertain cause of problem and rectify, replacing parts as required.

(iii) Reassemble and replace caliper.

April 2002

7 SPARES

7.1 CALIPER

Item Numbers refer to FIG.2 Quantities stated are per caliper

ITEM PART No. QTY. DESCRIPTION 8 7080207-Z 2 Pad Assembly

6000360 Seal Kit Comprising Items 5 & 6

7.2 INTENSIFIER

Repair Kit – Seals and diaphragm Part No. 7903162

Parts List for 20:1 Intensifier (Mineral) – 8400247

Item No.

Component Part No. Qty

1 Brake Chamber 8400233 1 4 Bracket 7952498 1 5 Label 7903161 1 9 Adaptor M22 x 1/8”NPT 7351304 1 10 M12 Bonded Seal 7301060 1 14 M8 Nyloc Nut 5100135 4

Appendix A

April 2002

APPENDIX A

M

A pp en di x

A pr il

A pp en di il

A pp en di il

A pp en di il

A pp en di il

A pp en di il

Appendix B April 2002

APPENDIX B

A pp en di

B il

A pp en di

B il

The Metric System and Equivalents

Linear Measure Liquid Measure

1 centiliter = 10 milliters = .34 fl. ounce 1 centimeter = 10 millimeters = .39 inch 1 deciliter = 10 centiliters = 3.38 fl. ounces 1 decimeter = 10 centimeters = 3.94 inches 1 liter = 10 deciliters = 33.81 fl. ounces 1 meter = 10 decimeters = 39.37 inches 1 dekaliter = 10 liters = 2.64 gallons 1 dekameter = 10 meters = 32.8 feet 1 hectoliter = 10 dekaliters = 26.42 gallons 1 hectometer = 10 dekameters = 328.08 feet 1 kiloliter = 10 hectoliters = 264.18 gallons 1 kilometer = 10 hectometers = 3,280.8 feet

Square Measure Weights

1 sq. centimeter = 100 sq. millimeters = .155 sq. inch 1 centigram = 10 milligrams = .15 grain 1 sq. decimeter = 100 sq. centimeters = 15.5 sq. inches 1 decigram = 10 centigrams = 1.54 grains 1 sq. meter (centare) = 100 sq. decimeters = 10.76 sq. feet 1 gram = 10 decigram = .035 ounce 1 sq. dekameter (are) = 100 sq. meters = 1,076.4 sq. feet 1 dekagram = 10 grams = .35 ounce 1 sq. hectometer (hectare) = 100 sq. dekameters = 2.47 acres 1 hectogram = 10 dekagrams = 3.52 ounces 1 sq. kilometer = 100 sq. hectometers = .386 sq. mile 1 kilogram = 10 hectograms = 2.2 pounds 1 quintal = 100 kilograms = 220.46 pounds Cubic Measure 1 metric ton = 10 quintals = 1.1 short tons

1 cu. centimeter = 1000 cu. millimeters = .06 cu. inch 1 cu. decimeter = 1000 cu. centimeters = 61.02 cu. inches 1 cu. meter = 1000 cu. decimeters = 35.31 cu. feet

Approximate Conversion Factors

To change To Multiply by To change To Multiply by inches centimeters 2.540 ounce-inches newton-meters .007062 feet meters .305 centimeters inches .394 yards meters .914 meters feet 3.280 miles kilometers 1.609 meters yards 1.094 square inches square centimeters 6.451 kilometers miles .621 square feet square meters .093 square centimeters square inches .155 square yards square meters .836 square meters square feet 10.764 square miles square kilometers 2.590 square meters square yards 1.196 acres square hectometers .405 square kilometers square miles .386 cubic feet cubic meters .028 square hectometers acres 2.471 cubic yards cubic meters .765 cubic meters cubic feet 35.315 fluid ounces milliliters 29,573 cubic meters cubic yards 1.308 pints liters .473 milliliters fluid ounces .034 quarts liters .946 liters pints 2.113 gallons liters 3.785 liters quarts 1.057 ounces grams 28.349 liters gallons .264 pounds kilograms .454 grams ounces .035 short tons metric tons .907 kilograms pounds 2.205 pound-feet newton-meters 1.356 metric tons short tons 1.102 pound-inches newton-meters .11296

Temperature (Exact)

°F Fahrenheit 5/9 (after Celsius °C temperature subtracting 32) temperature