561A4-23-101 RFI - Responses-2.pdf

561A4-23-101 RFI – Responses-2

RFI 01- Existing Steam Pressure Reducing Valves During the site walkthrough, existing steam pressure reducing valves (PRVs) were observed at several water heaters. Some PRVs are still connected, while others appear to have been removed or bypassed.

1) The contract drawings identify the steam pressure serving the water heaters but do not clearly indicate whether the existing PRVs are to remain or be replaced, please clarify?

RESPONSE: Existing PRVs are not intended to remain and should be removed if they fall within demolished steam piping.

2) Are the existing PRVs to remain, be removed, or be replaced? If replacement is required, please provide the required PRV specifications and operating pressures?

RESPONSE: No PRV replacement is required, and no PRV specifications or operating pressures are provided—water heaters are designed to operate at the building steam pressures shown (15, 25, or 30 psig depending on building).

3) Where an existing PRV is present but not shown on the drawings, should the new water heater be connected downstream of the existing PRV or directly to the steam system shown on the drawings?

RESPONSE: Where an existing PRV is present but not shown, the new water heater must be connected directly to the steam system per the drawings; undocumented PRVs should be removed or bypassed.

The contract drawings do not include any steam pressure reducing valves (PRVs).

These conclusions align fully with all mechanical, plumbing, demolition, schedule, and schematic drawings in the provided 100% DD set.

RFI 02 – ProPress for Domestic Water Piping The project requirements call for soldered copper piping. However, during the site walkthrough, existing press-type fittings were observed throughout portions of the domestic water systems.

1) To help reduce domestic hot water shutdown time, please confirm whether Viega ProPress or approved equal may be used for new domestic water piping.

Please confirm approval for:

Domestic Cold Water (DCW) Domestic Hot Water (DHW) Domestic Hot Water Return (DHWR) If approved, please provide any specific manufacturer or installation requirements.

RESPONSE: VA Plumbing Design Manual 4.4.2(g): “Use of press-connect type fittings is prohibited. They may only be used in an emergency and will be replaced with approved fittings within six (6) months of emergency. Notice must be provided to VHA/Healthcare Environment and Facilities Program (HEFP) via email to VHAHealthcareEng@va.gov upon installation and replacement of press-connect type fittings.”

RFI 03 – Domestic Hot Water Recirculation Pumps The drawings indicate replacement of the existing domestic hot water recirculation pumps. The proposed water heater package appears to include one pump per new water heater; however, existing conditions do not always match this arrangement. For example, Building 143 currently has three recirculation pumps.

1) Please confirm whether the contractor is to:

Replace the existing pumps one-for-one, matching the existing quantity and arrangement in each building, or install the pump quantity provided with the new water heater package?

If additional pumps are required beyond those included in the equipment package, please provide the required pump selections?

RESPONSE: Contractor shall replace the existing pumps one-for-one. Note that pumps included with water heater are referred to as NYC trim option as shown on drawing sheet P-701 and are provided by the water heater manufacturer as an option. NYC trim option shall be installed where existing. Contractor shall provide the domestic hot water recirculation pumps as listed on P-601.

RFI 04 – Building 3 Condensate Return Unit The drawings indicate a new condensate return unit for Building 3. An existing condensate receiver/pump is currently located near the existing water heaters.

1) Is the new condensate return unit replacing the existing unit, or is the existing unit to remain with the new unit being added?

2) If the existing unit is being replaced, please identify the required demolition and connection point for the new unit?

RESPONSE: Existing condensate return unit is shown on drawings for reference only. Existing condensate return unit is not dedicated to the domestic hot water heaters. New condensate return unit will be installed and piped to suction side piping of the existing condensate return unit.

Refer to 2/M-101.

RFI 05 – Domestic Hot Water Shutdown Requirements Replacement of the mixing valves, isolation valves, and final piping connections will require temporary shutdowns of the domestic hot water system.

1) Please provide the maximum allowable domestic hot water shutdown duration for each building?

2) Can shutdowns occur during normal working hours, or are off-hour shutdowns required?

3) How much advance notice is required?

4) Is temporary domestic hot water service required if the shutdown exceeds a certain duration?

5) Are the shutdown requirements different for Buildings 3, 7, 54, and 143?

RESPONSE: As the VA prepares for winter, domestic hot water shutdowns will need to be scheduled at least seven days in advance to ensure all parties involved are properly notified.

Shutdowns may occur between 8:00 a.m. and 4:00 p.m. (off-hours shutdowns will depend by building), and the requirements remain consistent for all buildings. No temporary domestic service is required. Please inform the COR to begin the shutdown scheduling process. G-001 notes #4, 5, & 18 indicate the conditions for shutdown requests and temporary service considerations. Note that the existing domestic hot water heaters are configured in redundant manner, which should minimize service shutdown durations.

RFI 06 – Isolation Valve Replacement / Phasing The demolition drawings indicate removal of the existing domestic water / steam / condensate piping back to the nearest isolation valves. Replacement of these valves may require shutting down the building domestic water system.

1) Please clarify the required sequence of work?

Should the contractor:

Perform one coordinated shutdown and replace the required isolation valves for both water heaters, with temporary piping/reconnection as necessary to maintain hot water service while the new heaters are installed; OR Replace the isolation valves as each individual water heater is replaced, resulting in multiple shutdowns?

Please confirm the preferred sequence and maximum allowable shutdown duration?

RESPONSE: Perform one coordinated shutdown per building and replace the required isolation valves for both water heaters, with temporary piping/reconnection as necessary to maintain hot water service while the new heaters are installed. Sequencing that has minimum shutdowns and disruption to the facility are to be coordinated with the COR for approval.

RFI 07- Is there an exact number of Mixing Valves to be included with the change out of these water heaters and if so, what are their sizes?

RESPONSE: Please refer to the schedule on drawing sheet P-601.

RFI 08- In the scope it mentions concrete pads to be added and replaced at the pre-bid site visit, there are some large concrete pads that when asked about we are told will stay (example pad at Bldg. 143 to stay we had been told).

RESPONSE: Please refer to G-series drawings. Bldg 7. requires a new concrete equipment pad.

Regarding Bldg. 143, a new 4” concrete topping shall be added to the existing housekeeping pad. Please refer to drawing sheets G-105 and G-501 for additional information regarding Bldg.

143 specifically.

RFI 09- Are all these new water heaters getting condensate piping to existing floor drains? If so, can said drains be identified?

RESPONSE: Each installation requires relief valve and overflow to be piped to the nearest floor drain.

Within drawings, floors drains are indicated by the following symbol:

RFI 010- Can the breakers to these HW heaters be identified so we know what needs to be shut off and isolated for swap-outs?

RESPONSE: Please refer to the electrical panel schedules on sheet E-601. Note that the symbol (+) is used to indicate the new loads. Schedules were developed based upon available documentation and panel schedules. Contractor to verify during installation.

RFI 011- At walk through it was mentioned the SOW was to be updated, and 2 Hot water heaters are going to be removed from the scope, will this revised SOW come out as part of these RFI answers?

RESPONSE: The two water heaters in Building 53 were removed from the SOW in Amendment 0001.

RFI 012- Will any of the buildings that we are working on require a temporary Hot Water Heater?

RESPONSE: No. Since each building is equipped with two water heaters, one will remain in operation while the other is being replaced. This ensures that the buildings continue to have a constant supply of hot water. Note that the existing domestic hot water heaters are configured in redundant manner, which should minimize service shutdown durations.