2 pipe with traps on rads. Where to set metering valve?

delcrossv

Conventional 2 pipe system with traps on each radiator. I'm putting in Mepco metering valves to replace broken inlet valves on the rads so I have adjustability. The Mepco valves have an adjustable orifice for use with Vapor(?) systems (replaces the orifice on the inlet).

Question is: do I set the orifice so the rad gets 80-90% filled like a vapor system, or leave it wide open?

Valve specs below

Jamie Hall

That's one of those questions… how big is a box? The metering orifice should generally be set so that the radiator is about 80 to 90 percent hot at the end of a long run. Then you can control the heat in the space by reducing the throttling valve (the accessible handle) to what you want.

Be aware that the above is pressure sensitive, and any adjustments should be made when the system is operating at its normal pressure — usually no more than a few ounces. Not that the valves can't be used on higher pressure systems — they can — but the orifice will be set smaller.

delcrossv

https://forum.heatinghelp.com/discussion/comment/1827638#Comment_1827638

@Jamie Hall even for conventional 2 pipe? It's not a Vapor system and runs at under 1 psi (but I could adjust it lower).

This is looking like a multivariate tweak between pressure and setting the stop.

Jamie Hall

The work fine on a conventional two pipe system. Just adjust the metering section to suit the system working pressure, that's all.

delcrossv

https://forum.heatinghelp.com/discussion/comment/1827642#Comment_1827642

Ok. I'll set it for 90% fill at the end of a long run and be done with it.

Thanks!

KarlW

If you are putting in new valves, have you considered Thermostatic Radiator Valves (TRVs)?

These can provide better comfort, but at a cost - your boiler gets (effectively) even more oversized as you may be heating 6 radiators instead of 10 at a time.

delcrossv

https://forum.heatinghelp.com/discussion/comment/1827645#Comment_1827645

Thought about it, but people will be monkeying with those as much as manual regulating valves.