ASME I Boiler with 15 PSI Pressure - Can I Use an ASME IV Safety Valve?

[EMANUELE GUERRINI]

Hi everyone,

I'm working in an Italian workshop certified under ASME Section I (Stamp S), and I need to build a boiler with a capacity of 1500 kg/h and an operating pressure of 0.98 barg (15 PSI). Since the pressure falls under the scope of ASME Section IV, I wanted to ask the following:

Can I use a safety valve certified under ASME Section IV, or does it absolutely have to be an ASME I valve, even though the pressure is low? I'm concerned about the long lead times and higher costs associated with ASME I valves.

Additionally, can I ship the safety valve separately from the boiler and have it installed later, as long as the valve meets the necessary certification requirements?

Any insights or guidance would be much appreciated! Thanks in advance.

 

[goutam_freelance]

According to the information available with me this boiler will be under Section IV(since the pressure is 15 psig) and the safety valve will also be under IV.

Also, the safety valve can be sent separately as suppliers of boiler and safety valves need not be the same as per ASME.

Engineers, think what we have done to the environment !

https://www.linkedin.com/in/goutam-das-59743b30/

 

[The Obturator]

See attached extract below from current ASME I (2023) Scope, particularly paragraphs PG-2.1(a) and PG-2.2.

Do also understand that a ASME I safety valve has different operational characteristics compared to a more simpler ASME IV valve, for example ASME I requires full opening at 3% overpressure.

If you're making the boiler to ASME I, your safety valve should also be made to ASME I requirements as per paragraph PG-2.2.

*** Per ISO-4126, the generic term
'Safety Valve' is used regardless of application or design ***

*** 'Pressure-relief Valve' is the ASME/API used term ***