Steam Safety Relief Valves-venting

[sterilizerman]

I am using Steam Relief Valves(Pressure) rated at 100psi.

I had a customer ask me to vent these to a sanitary sewer floor drain. Since this is steam under pressure dont they have to be vented to atmosphere either through a stand/vent pipe or to a gravel pit? Isnt thermal expansion a problem with going to a common floor drain?

Isn't venting steam under pressure to drain against code?

 

[jsummerfield]

Which code concerns your application, Fired or Unfired pressure vessel, piping, etc.? What industry? What country?

John

 

[sterilizerman]

Steam Boilers ASME Code Section 1 I believe. This a 24kw electrically heated steam boiler. Medical/Surgery BioMedical here in the U.S.

Facility has no standing vent pipe in place and boiler is in an interior room with no outside wall. Floor drain is available but have been told that all Steam Pressure reliefs should be vented freely to atmosphere. I dont think a gravity floor drain common to the facility drain line meets that requirement?

 

[deanc]

If you vent to sewer it will create a back pressue and you will lose your protection.

The sewer lines are not rated for pressure.

Municipal Codes prohibit discharge of steam in the sewer.

Talk to the Boiler Inspector or the Insurance carrier.

 

[davefitz]

If you vent it to the drain, it may cause an OSHA violation- someone may be working on the drain system, and could be hurt by any fluid over 140 F. It might be OK to drain the relief valve drips to the drain, but not the relief valve exhaust itself.

It shoud have its own vent to atmosphere, and maype a silencer if it is located in a city.

 

[GenB]

In the US, Mechanical/building Codes: bvent to the atmosphere & drain condensates to an approved drain.
It is customary for small steam boilers to 150psi to 25 BHP to be installed and pipe the vent (1 in ussually on 100psi blrs)
to vent to a standard floor sink (Plumbing Codes allows it)
and provided you follow the standard installation per Code (also Sanitary Codes are enforced within the Plumbing Codes)
and most of the building Inspectors will approve the installation.
We have worked on a lot of systems including sterilizers for hospitals and Labs (bio's my favorites). 'hope that helps
genblr