Tapping pipe for gauge

[acamato]

I want to install a gauge on the discharge side of my pump. I want to use the gauge to calculate flow. My issue is that I have a Hayward SP1486 union going from the pump to the multi-port valve. The SP1486 is a 10" long lexan elbow. The valve end is a self aligning union and the pump end has a compression fitting that threads into the pump.

Has anyone tapped this for a 1/4" NPT thread? Does any one know if it can be done?

 

[JohnT]

I'd think you'd be better off with a PVC T with a threaded port. You could adapt it down to your gauge size.

Are you looking for a problem between the pump and filter? Your filter pressure gauge should read the same as a gauge in that pipe.

 

[acamato]

The filter pressure gauge will not read the same as one directly off the pump. There is friction loss in the multi-port valve.

I cannot re-pipe between the pump and filter. Off the pump I have the SP1486 fitting which goes directly into the multi-port valve that is on the filter.

I want to compare my flow rate when I bypass the filter vs going thru the filter.

I am going to look at the pump (Super Pump) tonight to see if the side drain plug is on the discharge side of the pump. If it is, that will be my location for my gauge.

I want to also look at putting a gauge on the discharge side of the filter. The differential pressure between the filter gauge and this gauge will give you a true indication of how dirty the filter is.

 

[Bama Rambler]

Given that that little elbow costs in the neighborhood $60 I'd hate to ruin one trying to drill and thread it. While it should be possible because it's Lexan, do you want to take a chance?

 

[JohnT]

The filter pressure gauge will not read the same as one directly off the pump. There is friction loss in the multi-port valve.

But the gauge is on the inlet side of the multiport (between the pump and filter) when the valve is set to filter, not the outlet side. I don't believe you will see a difference on the readings.