Cross-section pipe issue.

[andrey7474]

Hi there.

I have a question. I will try to describe it shortly.

My refrigeration system has a water-cooled shell tube R22 condenser. The R22 inlet pipe has Ø 50mm (2 inches). The outlet pipe has Ø 40mm (1½ inches). I’ve installed the shutoff valve in the outlet pipe Ø 25mm (1inch). I used conical pipe reducers from both sides of the shutoff valve to install it. The valve is fully opened and R22 goes to the R22 receiver from the R22 condenser.

My question is: Could I have made some changes in my refrigeration system, especially relatively to condensing pressure and temperature by reducing the pipe cross-section with the shutoff valve?

Thanks in advance.

Andrei.

[RANGER1]

Andrey,
Any particular reason you put in smaller valve, was it all you had available?
If to small you could bank up liquid in shell & tube condenser causing higher discharge pressures.
Liquid receiver may not be able to breath or vent into condenser also not allowing to drain correctly.

[frank]

Are you talking about the water pipework or refrigerant pipework?

Seems strange that your inlet pipe size (50mm) is greater than the outlet pipe size (40mm)

[Tycho]

I'm guessing there is a 1" equalizing line from the top of the receiver to the top of the condenser.
so as long as the condenser is draining and you are not building up a level in the condenser itself I don't see any issue with it. (could be an issue when running high loads that the condenser doesn't drain fast enough)

However, using a correct size valve would save you some welding

[andrey7474]

Andrey,
Any particular reason you put in smaller valve, was it all you had available?
If to small you could bank up liquid in shell & tube condenser causing higher discharge pressures.
Liquid receiver may not be able to breath or vent into condenser also not allowing to drain correctly.

Hi RANGER1.

I installed the smaller valve because I didn't have any valves with a large diameter but I had to install it.

[andrey7474]

Are you talking about the water pipework or refrigerant pipework?

Seems strange that your inlet pipe size (50mm) is greater than the outlet pipe size (40mm)

Hello, frank.

I'm talking about outlet refrigerant pipe. The inlet pipe has a greater diameter because we have two R22 condensers and they work simultaneously. R22 goes to both R22 condensers through one pipe.

[mbc]

Hi

size of valves depending to our capacity ,
so in small size the DP (droop pressure ) is high,
also if you have not equalizing pipe you should go for larger size to let draining liquid from condenser and returning gas from receiver to condenser in this case of piping we should not have loop between condenser and receiver and slope of pipe should be high.

[andrey7474]

Hi

size of valves depending to our capacity ,
so in small size the DP (droop pressure ) is high,
also if you have not equalizing pipe you should go for larger size to let draining liquid from condenser and returning gas from receiver to condenser in this case of piping we should not have loop between condenser and receiver and slope of pipe should be high.

Hi, mbc

thanks for replying

I have the equalizing pipe between receiver and condenser and the valve on this pipe is fully opened.

[Segei]

Actually you can check temperature of the liquid going to the receiver. If liquid sub cooled, it means that you have some liquid at the bottom of the condenser.