Insulating Boiler Safety Valve

[Leuschna]

I have a request to insulate the safety relief valve on a firetube boiler. I can't find anything forbidding it in any applicable code, but I've never seen it done before. Anybody know for sure one way or the other? The site is in MD, if that helps.

Thanks!

 

[MJCronin]

What did the safety valve manufacturer say when you called them ?

What did the boiler vendor say when you asked that question ???

MJCronin
Sr. Process Engineer

 

[Leuschna]

Well, if anyone is interested, I heard back from the manufacturer. This is their policy:

1.) Insulation must not interfere with or block the drain or vent connections
2.) The test lever must not be interfered with in any way, and must be accessible and free to operate
3.) The method of insulation must take into account the potential for corrosion of the valve materials if moisture or condensate may accumulate.
4.) The method of insulation should be reviewed and approved by the local boiler inspector

Looks like common sense guidelines, but an inspector might still veto it.

 

[pmover]

whom is making the request? if it is the inspector, i would not hesitate to tell the inspector that insulation may jeopardize the operation of the valve for the valid reasons provided by the mfg. then follow-up w/ why, where, and what type and get the inspector to approve the documentation (likely won't happen). like yourself, not aware of code requirements, but see the below image from b31.1

hot insulation is generally applied for personnel protection. the firetube boiler safety valve are generally located where personnel do not routinely access.

all 4 guidelines are valid.

during my boilermaker days, i never saw insulation on boiler safety valves. this also applies to my sailor days.

 

[Leuschna]

It was requested by the client at a pharmaceutical plant. They are very particular about their process setup and the policies drift into the boiler room sometimes. At this point, I am going to advise against it, but if they push for it, it will be up to their inspector to make the call.

 

[Dhurjati Sen]

Dear Leuschna,

I have seen Indian, Italian, Japanese and Korean boilers. None of those had insulated safety valves.

Reason: Floatation test of the PSVs is common and it is done while the boiler is in operation. You need to gag two PSVs while floating one.

Still, to clear all doubts, do contact the boiler manufacturer, as they always have the last word. You could be surprised if these guys really offer you partly insulated PSVs.

Regards.



DHURJATI SEN
Kolkata, India