check valve to divert full pressure from heat pump? Is this right?

[johnxxx]

So the question I have is this is a brand new pool setup and the plumbers who came out to hook up my equipment placed a check valve in this location as shown in the picture. The plumber told me that they need to do this because heat pumps would have too much pressure going to them if the PVC line went right from the filter outlet to the heater inlet. It would put too much pressure in the heater lines and cause damage. They said they only do this with heat pumps on all there installs and not other type of heaters. Does this seem right to you guys? I'm thinking that I'm not going to get the most from my heat pump because some of the water will be able to bypass the heater essentially. Thoughts?

Equipment: 2 HP Jandy Pro pump, Jandy Filter Cartridge CL460, AquaCal SQL 175 heat pump, Jandy PLC1400 SWG

 

[johnxxx]

I did some research and might of answered my own question. AquaCal sells a Bypass Valve Kit ( Kit STK0135 )... here's how they advertise it:
5 lb Bypass Valve Kit (Kit STK0135)
When high flow rates are outside recommended tolerances, please use this kit or an alternative bypass valve system.
This kit can be used to control excessive water flow through the heat pump. It provides automatic flow adjustments for most applications.

So it does state in there "...or an alternative bypass valve system" so now I'm thinking that this setup is correct. Here's a picture of the model number of my check valve. It a Hayward PSCV2S2DGR PVC Check Valve, 2" by 2.5" and the valve mechanism is spring loaded. ( Spring/flapper is towards top of valve so flow is from top to bottom )

According to AqualCal's owners manual my minimum flow rate for the SQ175 is 30 GPM and Maximum flow rate is 70 GPM.

I'm now considering purchasing one of those flow meters and insert it after the filter to determine my flow rate.

 

[griffths]

I am no expert on heat pumps and bypass loops but what your plumber has done doesnt appear to accomplih anything useful or controlable as there is no way to comtrol the amount of water bypassing the heater so it may be all of it or nome or, more likely, something in between. I would argue that a valve in place of the check valve would have been a better solution.

 

[johnxxx]

Thx Jay .....I'm thinking along your same lines however even with a ball valve ( and you control how opened it is ) one would need a flow meter to determine even if this is required or how much to 'open' the ball valve itself if it was exceeding the 70 GPM maximum of the heater. This heater is 4 years old and I used it with my 20,000 AG pool with direct 1.5 inch PVC going to it and from it from a 1.5 HP pump rated at 60 GPM and never thru a code about flow on the heater itself. ( I guess I was more concerned about meeting the minimum requirements rather than maximum ). My current pump model is a Jandy PHPM2.0 and it rated at Max 80 GPM.

As a side - I'm really thinking about removing this PVC piping all together and redoing it with only a flow meter which I was planning on getting anyway to determine turn over of my ~30,000 gallon pool. I'm waiting for plaster at the moment but it should be done w/i the next 2 weeks... I get concrete around the pool next week. Been too busy to start a thread but might do one shortly as I have a ton of pictures during each build stage.

Here's the picture of AquaCal's 5LB Bypass....

 

[PiperVon]

There is a huge difference between "Flow" and "Pressure". What your Plumbers did will be fine, both lines will have the same "Pressure" however the flow that the heater cannot handle will be bypassed thru the "Check Valve". Sleep tight!