4520--Heater Bundle Replacement in Boiler Plant One Time Repair

The purpose of this amendment is to answer questions that were received (see below) and to extend the response date and time to 2:00pm MT 8/6/2026

1. The price schedule identifies 1/2-inch and 3/4-inch NPT control valves, while the SOW identifies existing Siemens MVF461H50-30 and MVF461H32-12 valves, which are flanged DN50 and DN32 models. Please confirm whether the replacement valves must match the existing sizes and connections or the NPT sizes listed in the price schedule. If the valves are to be resized for the current load, please provide the applicable steam pressure, temperature, flow, and load data.

1. The replacement valves must be like-in-kind with the existing Siemens MVF461H50-30 and MVF461H32-12 valves — matching the existing flanged DN50 and DN32 sizes and connections, consistent with the NPT sizes listed in the price schedule.

1. The SOW does not identify a site-visit opportunity, and a prospective mechanical contractor has requested a walkthrough to verify existing conditions for pricing. Please confirm whether the VA can accommodate a site visit. If a site visit cannot be scheduled, please provide any available photographs or drawings showing the tube-bundle removal clearance, existing control-valve arrangement, and proposed locations for the three secondary steam isolation valves.

A site visit cannot be conducted at this time. In lieu of an in‑person assessment, I have attached photographs that capture the requested information.