Regulation covering domestic heater pressure relief devices

[asimpson]

I am woring on design of domestic water heater that will use pressure relief to protect from explosive pressure failure.

Enclosed medium is steam and air in small volume 1-2 liters.
Normal working maximum presure 10 bar.

Assuming world-wide usage, where would I look for guidelines, regulations and safety criterian that would cover the implimentation of such a device?


Many thanks.

 

[HPost]

For EU use, the product will have to have a CE mark and will therefore need to confirm to the pressure equipment directive.

I am not sure of the ROW requirements though.

Cheers

Hpost

 

[Pud]

BS5386 used to be the UK* standard for gas appliances. Probably an ISO now.
Large standard so you will need to check which part you need.

Many years ago it was the British Gas purchasing requirements before they were privatised...

H

www.tynevalleyplastics.co.uk

It's ok to soar like an eagle, but weasels don't get sucked into jet engines.

 

[Pud]

Just found this - take your pick: CH Boilers

H

www.tynevalleyplastics.co.uk

It's ok to soar like an eagle, but weasels don't get sucked into jet engines.

 

[chicopee]

I am not familiar with steam and air domestic water heaters. Are you sure that the system is not, either, a hot water heater or a steam boiler in which you have a tankless water heater? According to the ASME/NB rated valves, a safety valve for the steam boiler would have a set pressure at or less than the MAWP of the boiler with a relieving capacity (in lbs/hr) not to exceed the heat input to the boiler; if you have a hot water heater, the pressure relief valve should have a set pressure not to exceed the MAWP and a relieving capacity (in btu/hr) with a thermal element of 210 dF not to exceed the heat input.

 

[MintJulep]

Following Pud's link found

http://shop.bsigroup.com/en/ProductDetail/?pid=000000000030160134

From there I'd take a peak (by title at least) of all the listed cross-reference standards too.

 

[asimpson]

Thanks everyone.

This is a new product with unusual characteristics.



The heating chamber is allowed to run dry at high temperatures in normal operation. This chamber is vented to athmosphere when not producing steam. However if a catostrophic failure and vent becomes blocked and pressure is not relieved through output then the heating chamber effectively becomes presurised by captive steam. A pressure relief valve will release this pressure below SWP. I am concerned PRV will be subjected to temperatures in excess of 200C and become comromised. If it fails open this is not a problem.

I would like to know if there are any regulations that may address this eventuality.

 

[asimpson]

I am looking for regulations covering devices similar to this:

http://www.showerspares.com/triton_...r/triton_pressure_relief_device_prd_82800450/

Used in electric shower heaters.

Thanks

 

[MintJulep]

Have you considered a fusible plug rather than a valve?

 

[ScottyUK]

Does this put you on the right track for standards?

http://media.wattswater.com/PG-TP-ASME.pdf

Reliance Water Controls in the UK also make TPRV's but I haven't managed to find a datasheet online to link to. If you want to look then TPR 15, TPR22, TPR28 are the ranges I'm aware of, but they are all soft-seated with a brass plug sealing against a silicone disc.

 

[chicopee]

I don't know where you are located but the link"

http://www.showerspares.com/triton_shower_spares/t..."

that you posted shows relief valves that would be unacceptable in the US. You have to have a certification recognized in the US such as UL, ASME or NB. Plastic relief valves wont cut it in the US at the present. Forget about fusible plugs since these can not be manually or hydraulically tested and would be used on media that would be hazardous to the environment or the public.