140R4023R0014_Questions_and_Answers_-_Amendment_0003_0003.pdf

140R4023R0014 – Butterfly Valve Replacement at Blue Mesa Powerplant

Amendment 0003

Questions (# 1 through 51) and Answers

Posted August 29, 2023

1) In section 35 22 15 article 1.04 J.6. It is stated that the valve be capable of opening against a differential head of 156 psig, which corresponds to the full normal head. In modern hydro industry standards, the plug is eccentric relative to the axis of the trunnions, which prevents friction of the seal when moving in the closing position, but also gives a strong closing tendency when the valve is closed. It is strong enough that it is impossible to open the valve with the full normal head as a pressure differential, even with the servomotors pushing at full strength towards the open position. This is an added layer of safety protecting workers that may be located in the water passages from an unexpected ‘open’ command. The opening is normally only done when the pressure is balanced with only 20% of the normal head as a differential.

Please check the requirement. Article 1.04 O) requests double eccentric plugs, as is typical.

Answer: The turbine shutoff valves are not required to open against a differential head of 156 psig with the downstream turbine wicket gates closed. The turbine shutoff valves are not required to open except under near balanced pressure conditions. The turbine shutoff valves are required to close against a differential head of 156 psig under full flow conditions per Section 35

22 15 paragraph 1.04 I 5.

2) In section 35 22 15 article 2.01 B.1 it is requested that there be dual single acting control cylinders with counterweights (potential energy drop). However, based on the plant drawings provided, for unit 2, there does not appear to be enough space between the valve and the left bank wall to allow the placement of a second cylinder or counterweight, unless the valve size is shrunk considerably. For uniformity between the two units, please consider the use of a single cylinder and counterweight.

Answer: Single acting hydraulic cylinders (not dual) with counterweight closure is acceptable for both turbine shutoff valves.

3) In section 35 22 15 article 2.01 B.11 l) it is stated that the hydraulic cylinder provide a constant torque for opening and closing. However, because the torque is created by a linear hydraulic cylinder, imparting a circular movement, the torque must necessarily be variable.

Please check the wording.

Answer: The intent of Section 35 22 15 paragraph 2.01 B 11 l is that the cylinder provides a constant speed across the majority of the cylinder travel. It is understood that the torque on the

TSV will vary.

4) In section 35 22 15 article 2.01 B.12 d.: please clarify your requests for the levers and weights.

Normally levers and counterweights are affixed to the side of the same trunnion which supports the valve plug. The weights of the levers and counterweights partially counteract the weight of the plug on the other side of the trunnion. Stiffness and deformation of the trunnion is managed through appropriate sizing of the trunnion and the stiffness of the plug. In any case, the weights are minor compared to the hydraulic loads on the valve.

Answer: Provide TSV manufacturers’ standard trunnion and bearing design for valves of this size and pressure rating. Valve shaft bearings shall be greaseless, self-lubricating type, in accordance with specifications Section 35 22 15 paragraph 2.01 B 12 d 7. Ensure valve trunnions and trunnion bearings are designed for all loading from the counterweight, hydraulic cylinder, and water pressure.

5) In section 35 22 15 article 2.01 B.12 e: Please clarify the extent of the safety cage requested.

Does it need to encompass the entire sweep of the lever and the counterweight, on the entire height?

Answer: The safety cage shall encompass the lever and counterweight through its entire range of motion.

6) Regarding specification section 35 22 14, Valves and Equipment, AND section 35 22 15, Turbine Shutoff Valves, there are various named valve manufacturers. It’s also noted ‘or equal’ is acceptable; what is needed to submit as part of the process for a valve manufacturer to become

‘or equal – Approved’, prior to bid date.

Answer: Valves from any manufacturer are considered in the Government’s review of proposals.

Contractors must submit data indicating manufacturer’s valves or products meet the specified requirements.

7) Regarding specification 35 22 14, Valves and Equipment, 1.04., F., Bypass Line Valves – is it imperative to offer 16” valves? Most flow control valves are sized to an application – and not necessarily to fit a pipeline size. Please clarify if it is acceptable to offer, as part of the base bid, a bypass line and valve system that may be smaller, or larger if necessary, than 16”?, as long as it meets/exceeds the specified performance criteria.

Answer: Smaller or larger bypass line and valves may be considered if they meet the requirements contained in specifications Section 35 22 14. Valves and valve diameters are subject to Government approval.

8) Section 01 14 12 – 2, Q. states: Fabrication and shipment of two 149-inch diameter or larger

TSVs, actuators, and appurtenant equipment to Blue Mesa Powerplant shall not exceed duration of 24 months. This statement is to mean that butterfly type TSVs with diameter between 149” –

156” would be acceptable to the Government. Is this correct? If it is determined that a smaller valve diameter has better performance, is it still required to propose a 156” design as the base bid? I.e. does USBR require base bid plus optimized design? Or is optimized design alone permitted as a base bid?

Answer: Provide 156-inch diameter TSVs in accordance with Specifications Section 35 22 15 paragraph 1.04 and as shown on drawings 622-D-60045 through 622-D-60047.

9) Section 35 22 15 2.01 A.6 g. requests steel mounting pads to mount the actuator on the side of the valve body. However, for a valve this size, linear cylinders are required and these should be mounted on the floor, as the existing configuration similar to what is shown on drawing 622-D-

60046 that you have provided with the informational drawings. Please reconsider the requirement.

Answer: Provide TSV manufacturers’ standard actuator mounting design for valves of this size and pressure rating. A floor mounted operator with appropriate baseplates as shown in 622-D-

60046 would be acceptable.

10) Section 35 22 15 2.01 A.9 b. requires stub shafts that extend into the TSV disc at least 1.5 shaft diameters. This requirement appears to apply to the lens type designs such as the current configuration. In article A7.e of the same section, it is requested the valve disc be of the ‘flow through’ design (also called bi-plane or lattice). This type of disc is superior to the older lens-type disc designs as it provides better stiffness per weight and a lower loss coefficient, allowing the water to flow through the center. To resist the immense forces of the closed valve, large trunnion sizes are required. The extension of these shafts by 1.5 times the shaft diameters would create an unnecessary obstruction into the water passage at the center of a flow through type disc. This extension of the shafts into the disc is presumably to allow the bending forces to be transmitted through the section of the shaft. The bending forces can also be transmitted using bolting, which does not require the stub shaft to protrude into the body and frees up the space in the center of the disc. Please reconsider this clause to allow efficient disc design.

Answer: The 1.5 stub shaft diameter extension into the valve disc is a conservative requirement based on AWWA butterfly valve standards. If the contractor can provide calculations and analysis showing a shorter extension of the stub shaft into the valve disc will meet all allowable stress requirements of specification Section 35 22 15 paragraph 2.01 A 1 through 12, the shorter stub shaft design would be acceptable.

11) The specification requires the valve supplier to perform pre-disassembly testing on the butterfly valves, to measure the flow and establish the head loss and Cv. Could USBR please confirm the location of the taps that would be used to test? The taps do not appear to be identified on the drawings.

Answer: The recommended procedure to measure the flow and establish the head loss and Cv can be found in Section 51 00 20 – Blue Mesa BFV Pressure and Flow Data Collection. The recommended pressure transducer locations are as follows:

• Upstream pressure transducer: Locate on the domestic water supply piping shown on drawing 622-D-462, Drawing Sheet 52.

• Downstream pressure transducer: Locate on the unit gauge board penstock pressure connections. The piezometer taps for the unit gauge board piping are shown on Drawing

Sheet 112, Blue Mesa Power Plant – Transverse Section Through Unit – Turbine

Acceptance Text.

12) The specification requires the supply of a 149” ellipsoidal dish head for the butterfly valve.

Can you confirm that this dish head is required by USBR to be bolted to the upstream flange of the penstock in the occurrence that water would need to be passed through the ring follower gates?

Answer: Yes, the 149-inch ellipsoidal dished head is required so that it may be connected to the

149-inch diameter flange upstream of the TSV. Refer to section 01 14 12, Work Restrictions, for additional information.

13) SECTION 01 14 12, WORK RESTRICTIONS, 1.04.R.1.c (page 2)

If removal and installation is delayed according to this paragraph, can equipment be stored on site?

Answer: Storage areas will be permitted in accordance with the approved Facilities Use

Rehabilitation Plan (RSN 01 14 10-1) Refer to section 01 14 10 – Use of Site for additional information.

14) SECTION 01 31 19

PROJECT MANAGEMENT AND COORDINATION

1.04.A 3. (page 3) Design Coordination Conference

What is the expected length of design coordination conference?

Answer: 3 days. Shorter or longer durations are acceptable to achieve purpose in accordance with specifications Section 01 31 19 paragraph 1.04 A 3 c.

15) SECTION 01 33 00

SUBMITTALS

Table 01 33 00A List of Submittals (page 16)

33 22 15: What is the due date of the 1st TSV submittal to be provided from valve manufacturer for approval?

Answer: Submittals are to be submitted in accordance with Table 01 33 00A – List of

Submittals. Submittals that are action type require approval from the Government.

16) SECTION 09 96 20

COATINGS

1.03.D Submittals (page 3)

RSN 09 96 20-3, Paint Chip Samples:

Are paint chip samples required for TSV´s and pipe spools?

Answer: The TSV’s and pipe spools require paint chip samples. Specification section 09 96 20 paragraph 3.09 identifies the equipment requiring coatings/linings. Specification section 09 96

20 paragraph 3.10 identifies the requirements for color schedules.

17) SECTION 09 96 20

COATINGS

3.09 tabulation 05 – Butterfly Valves (page 22)

Are substitute epoxy coatings from other manufacturers acceptable that are equal to the specified coatings?

Answer: Yes, refer to specification Section 09 96 20 paragraph 1.03 B 3 for substituted coating materials.

18) SECTION 35 22 14

VALVES AND EQUIPMENT

2.01.K.1.b./c/d/e (page 14)

What grade of stainless steel is required?

Answer: Manufacturers’ standard grades of stainless steel are required.

19) SECTION 35 22 14

2.02.L.1. (page 15)

Is AUMA actuator an acceptable equal to the specified actuator?

Answer: Equivalent motor-operators, such as those manufactured by AUMA, would be evaluated during the Government’s review of proposals. Contractors must submit data indicating products meet the specified requirements.

20) SECTION 35 22 14

2.02.L.1.b (page 15)

Confirm that actuator specified is for open/close service on no modulation service.

Answer: The actuator is required to provide open/close and modulating service.

21) SECTION 35 22 15

TURBINE SHUTOFF VALVES

1.04.C (page 3)

Can pipe spools be furnished by a qualified third-party pipe supplier/fabricator (in lieu of valve manufacturer)?

Answer: Yes. Pipe spools should be manufactured in accordance with specification Section 35

21 95 – Metal Piping. Pipe spools can be supplied by a different manufacturer than the valve manufacturer.

22) SECTION 35 22 15

SHUT OFF VALVES

1.04.G 1 (page 4)

It is understood that the contractor to determine if air valves are required for proper operation of

TSV´s. Advise where pricing to be added for such additional items (if required).

Answer: Yes. Amendment with updated Specifications will be issued at a future date, currently anticipated to be posted by September 8, 2023.

23) SECTION 35 22 15

1.04.R (page 6)

Can the equivalent European standard be substituted for the specified ASME Section VIII Div.1 requirements?

Answer: The valves flanges, body shell stresses, and allowable stress shall be in accordance with

ASME BPVC Section VIII, Div. 1. European standard equivalents would be considered. The

Contractor shall be responsible for showing the standards to be equivalent.

24) SECTION 35 22 15

1.06.E (page 13)

Can the equivalent European standard be substituted for the specified ASME Section IX

Answer: European standard equivalents for ASME BPVC Section IX would be considered. The

25) SECTION 35 22 15

2.01.A. 9.b. (page 20)

The 1.5 shaft diameter insertion depth will have a negative impact on cv-value of the TIV´s and therefore we´d like to understand if the 1.5 shaft diameter insertion depth can be reduced, providing that all other aspects of the specification pertaining torque, strength, shear, etc are met?

Answer: The 1.5 stub shaft diameter extension into the valve disc is a conservative requirement based on AWWA butterfly valve standards. If the contractor can provide calculations and analysis showing a shorter extension of the stub shaft into the valve disc will meet all allowable stress requirements of specification Section 35 22 15 paragraph 2.01 A 1 through 12, the shorter stub shaft design would be acceptable.

26) SECTION 35 22 15

2.01.B. 3.b./5. (page 22)

Confirm that locking mechanism is required on the actuator and not on the TSV body.

Answer: Locking mechanism shall be on the actuator in accordance with specifications Section

35 22 15 paragraph 2.01 B 3 b and 2.01 B 5.

27) SECTION 35 22 15

2.01.B. 6. (page 22)

Usually, TSV´s are open or closed, but not operated in intermediate positions. For better understanding we´d like to know why the actuator should hold the TSV disk in any intermediate positions between fully-open and fully-closed.

Answer: The TSV is intended to be operated in the opened or closed position. It is not anticipated to operate in intermediate positions. However, the actuator shall be designed to hold the TSV disc in intermediate positions in accordance with specifications Section 35 22 15 paragraph 2.01 B 6.

28) SECTION 35 22 15

2.02.A (page 25)

Can the equivalent European standard be substituted for the specified ASME BPVC Section VIII

Div. 1 requirements?

Answer: European standard equivalents for ASME BPVC Section VIII, Division 1, would be considered. The Contractor shall be responsible for showing the standards to be equivalent.

29) SECTION 35 22 15

2.03.A.3/4/5/6. (page 27)

Can the equivalent European standard be substituted for the specified ASME BPVC Section IX

Answer: European standard equivalents for ASME BPVC Section IX would be considered. The

30) SECTION 35 22 16

HYDRAULIC OPERATING SYSTEM

1.04.A. (page 3)

Are there any brand preferences or restrictions for HMI and PLC?

Answer: No brand preferences or restrictions if the manufacturer meets the specifications requirements.

31) SECTION 35 22 16

HYDRAULIC OPERATING SYSTEM

2.02.C.1.a. (page 16-17)

May components nameplates be polyester raised panel labels, white finish with black text, compliant with UL 969, rather than engraved labels? Major equipment labels shall be engraved nameplates as described.

Answer: Provide engraved nameplates in accordance with specification Section 35 22 16 paragraph 2.02 C 1.

32) SECTION 01 33 26

ELECTRICAL DRAWINGS AND DATA

1.04.E.2.a. (page 4)

Is selective coordination required among overcurrent protection devices?

Answer: Yes. Protective devices should be coordinated to the greatest extent possible.

33) Could you advise where the TSV access point-manhole is located? Is there one located in the upstream side of the TSV?

Answer: There is a manhole located in between the sleeve type couplings, on both the Unit 1 and

Unit 2 penstocks, in the Penstock Gallery downstream of the existing TSVs. There are no manholes upstream of the TSVs.

34) Is there any drainage point between the Flat Wheel Gate and the TSV (except the drain on the TSV visible in the drawing below)?

Answer: There are no additional drainage points between the TSVs and the Fixed Wheel Gates.

The 6-inch drain is provided and is located inside the powerhouse. The drains are located just below the 156-inch butterfly valves inside the powerplant. The drains were functioning properly during the examination last penstock examination in April 2015.

35) Is there a sump linked to the TSV drainage valve?

Answer: The TSV drain valves and piping feed a sump that is evacuated by two 3,000 gallon-per minute deep well turbine-type pumps which pump from the sump into the tailrace.

36) Is there any drainage point between the Flat Gate Wheel and the Intake structure?

Answer: No additional drainage points existing between the fixed wheel gate and intake structure.

37) Do you have dewatering procedures? Is there a specific one that covers the dewatering of the upstream of the TSV with the TSV closed? If so, could you share it?

Answer: Reclamation’s Standard Operating Procedure for the facility includes procedures for unwatering and filling the outlet works and penstock system. The Government will investigate requirements for sharing dewatering/charging procedures, the results of which will be posted in a future amendment to the solicitation.

38) Could you share the expected leakage flowrate from the Fixed Wheel Gate?

Answer: Leakage rate unknown. Fixed Wheel Gate seal was sufficient, and leakage was low enough that the penstock was unwatered in April of 2015 for personnel to enter and inspect.

39) 35 22 15, 1.05, D., 4 a, We calculate our hydraulic actuators according AWWA C541-16; is this acceptable?

Answer: Actuator torque calculations shall be performed in accordance with AWWA M49 in accordance with specification Section 35 22 15 paragraph 1.05 D 4 a.

40) 35 22 15, 1.05, D., 5., c, c, Regarding FEA for valve, in lieu of every 10% stroke point for reference, may we offer fewer reference points (each 25% of stroke) of which we can extrapolate data?

Answer: Provide FEA model of the valve at every 10% opening from closed to 100% open in accordance with specifications Section 35 22 15 paragraph 1.05 D 5 c.

41) 35 22 15, 2.01, B., 11 e, Is Stainless Steel 1.4460 (AISI 329) acceptable?

Answer: Alternate stainless steel materials may be considered during Government evaluation of proposals, subject to Government approval.

42) 35 22 15, 2.01, B., 11. j, Similar as to 11., B., b., materials, may the control block be made of non-corrosive/coated steel? in lieu of a 100% stainless steel control block?

Answer: The control block shall be stainless steel in accordance with specification Section 35 22

15 paragraph 2.01 B 11 j.

43) 35 22 15, 2.01, B., 11, q, For Piping gland (fittings) are carbon steel zinc plated or stainless steel acceptable in lieu of Bronze?

Answer: The hydraulic actuator gland shall be bronze in accordance with specification Section

35 22 15 paragraph 2.01 B 11 q.

44) 35 22 15, 2.01, B., 11., s, Ports: SAE four-bolt flange, 1 ½ inches tubing size: The sizing of

1-1/2" tubing size seems to be oversized considering a stroke time requirement of around 3 minutes. We ask to use tubing size commensurate to design parameters. Please confirm.

Answer: The hydraulic actuator ports shall be SAE four-bolt flanges, 1½” tubing size in accordance with specifications Section 35 22 15 paragraph 2.01 B 11 s.

45) 35 22 15, 2.05, J., 4. a., Since the cylinder is custom made specific to the project, it is per our manufacturer practice for cylinder test to test block against blind end. Please confirm acceptable.

Answer: The piston shall not be blocked against the blind end of the cylinder for the tests in accordance with specifications Section 35 22 15 paragraph 2.01 B 11 s.

46) 35 22 15, 2.05, J., 5., c., Repeat the leakage test with the rod and piston at mid-stroke positions at 6-inch increments:, comment: yes, we can accommodate as an assembled unit with

TSV during tests.

Answer: Acknowledged.

47) 35 22 16, 1.05, C., 2., Confirm existing hydraulic piping, fittings, and components are rated to new hydraulic operating system pressure, if applicable. Comment: This is not applicable as new piping, fittings, etc. is expected.

Answer: Acknowledged.

48) 35 22 16, 1.05, C., 10., Regarding Electrical wiring, interconnections, and schematic diagrams, including ISA format process and instrumentation drawings, etc. May it be considered acceptable to use an ISA format equivalent such as IEC? Please confirm.

Answer: ISA format is required to be used.

49) 35 22 16, 2.01, F., Oil Pump, request for alternate design acceptance: We recommend a hydraulic oil pump on the HPU to be equipped with a redundant gear pump. (Not an axial piston pump). Advantages include lesser heat generation, as well as the HPU can be shut off main motor pumps to safe energy during holding valves open, closed or in intermediate position.

Please confirm.

Answer: Alternate oil pumps would be considered during Government evaluation of proposals, subject to Government approval.

50) 35 22 16, 2.01, I., Specified Flow control valve cartridge type differs from earlier specified

Flow Control valve requirements with adjustable throttles to set oil flow to the cylinder. Please clarify.

Answer: Provide adjustable cartridge type flow control valve in accordance with specifications

Section 35 22 16 paragraph 2.01 I.

51) 35 22 16, 2.02, -, CONTROL PANEL: Specification notes touch HMI, which means a local

PLC. Therefore, the hydraulic unit shall be equipped with a PLC (Like SIEMENS or Allen

Bradley?) Therefore no mechanical push buttons are to be used in case of HMI. All graphic interfaces and push buttons are to be included with this interface.

Answer: Control switches, pushbuttons, indicating lights, etc. are to be used as a backup for the

HMI.