HPS boiler plant

[cme]

I am reviewing a set of plans for a hospital boiler plant in PA. The existing boilers are being replaced by a Contractor. There are 3-400bhp-150lb Cleaver Brooks 4-pass boilers connected to a 8"HPS header.

For each boiler there is a stop/check valve on the outlet, ATC valve, short length of pipe then an elbow, then a straight pipe section with a orifice and meter, then a stop valve at the header.

My questions are:

Is it permissible per ASME Sec 1 to put the atc valve and orifice meter between the stop/check and stop valve. The piping between them has to be welded by ASME qualified welders. I haven't seen a detail yet showing a free blowing drain valve per ASME Sec 1 between the stop/check and stop.

I can't think of a reason to put a ATC valve there.

They indicate 2 separate bottom blowdown assemblies complete with quick and slow opening valves. Why 2?

Are blowdown separators or tanks permissible with current codes?

Its been a while since I put in a HP boiler plant.

 

[TBP]

In many jurisdictions, the piping you're asking about would fall under ASME B31.1. And what'a an "ATC" valve?

 

[cme]

sorry ...... "automatic temperature control" jargon which in this case is a 2 port control valve

just for laughs ..... I'd like to see the size actuator on that valve, 6" pipe I believe

 

[TBP]

What pressure will these boilers operate? If they're firing to maintain a header pressure of 125 PSIG, then you're likely looking at something like a 4" stop & check.

Why would a temperature control valve be required in the steam lead?

From the way you're describing things, I suspect that your high pressure steam boiler project is being handled by an outfit that normally does commercial hot water systems.