Rodi pressure gauge bouncing like crazy (help)

[the.cornish.reefer]

I've added a booster pump to my rodi unit, however since adding it when the pump is turned on the needle of the pump bounces up and down like crazy.
Now I'm wondering do I have air in the system?
Is the gauge rubbish?
Or is it something to do with the diaphragm in the pump?
below is how i have it set up.
Any help would be great, thanks

 

[mann1139]

Check valve might help.

When you say it's bouncing, what are the high and low of the range?

What is your input pressure as a reference to?

 

[lakai]

Normal

 

[the.cornish.reefer]

Check valve might help.

When you say it's bouncing, what are the high and low of the range?

What is your input pressure as a reference to?

Is quite hard to see, but looks like the low end is around 45psi and high end it around 90psi.

The pressure before and with the pump off is 35psi.

Going to install a check valve today and see if it helps, maybe also try a glycerin filled gauge too

 

[braaap]

Move the booster and gauge. Booster first. Then gauge. Before the sediment filter at the water inlet. Should fix most of your problems. It’s also the correct placement.

It’s placement after the first 3 stages is to protect it from sediment but that’s 100% not necessary unless you are filtering mud.

 

[the.cornish.reefer]

Update, fitted needle valve and gauge is all sorted

 

[exnisstech]

Update, fitted needle valve and gauge is all sorted

What is this needle valve? I've always been under the assumption a liquid filled gauge is needed to prevent the needle from bouncing.

 

[mann1139]

Move the booster and gauge. Booster first. Then gauge. Before the sediment filter at the water inlet. Should fix most of your problems. It’s also the correct placement.

It’s placement after the first 3 stages is to protect it from sediment but that’s 100% not necessary unless you are filtering mud.

I disagree with this.

The filters don't benefit from the higher pressure, but the pump definitely benefits from not seeing the gunk.

 

[Red_Beard]

does that needle valve significantly affect the accuracy of the gauge? like when you turn it on initially does it slooowly ramp up what the gauge reads or is it pretty instant? I had the same issue, but installed a pressure snubber inline instead. with the snubber there is still about 5 psi bounce when the pump actuates, whereas before it was like yours, 45-90 bouncing hard.

 

[the.cornish.reefer]

does that needle valve significantly affect the accuracy of the gauge? like when you turn it on initially does it slooowly ramp up what the gauge reads or is it pretty instant? I had the same issue, but installed a pressure snubber inline instead. with the snubber there is still about 5 psi bounce when the pump actuates, whereas before it was like yours, 45-90 bouncing hard.

I assume it's accurate, the gauge reads about 80psi.
My booster pump has no adjustment on it, and according to the specs of the pump the working pressure it's 82psi

 

[the.cornish.reefer]

What is this needle valve? I've always been under the assumption a liquid filled gauge is needed to prevent the needle from bouncing.

This is all I bought, worth a try for the money