"high flow" valves

[acman]

I just installed a Carrier 48TJE roof top unit.It has what they call high flow valves,one on the suction line,one on the discharge line.I've never seen these. It looks like a large access fitting.No threads...just a black plastic cap.I phoned Carrier and they were useless.In the literature,they call it a high flow valve that is not field serviceable.Anyone heard of these?

[Prof Sporlan]

Offhand, can't think of any reason why one would need a regulating valve in both the suction and discharge lines of a rooftop unit.

Perhaps they are simply full port ball valves? Perhaps they are being used in lieu of compressor service valves?

[condenseddave]

Were the caps removable? Was there anything under them if so?

What next?

[benncool]

Sounds like pressure relief valves. I've installed a lot of 48TJE's and can't imagine what acman is referring to. Can you post a picture?