@MJCronin - Just clarifying something here, in the thread you've cross posted. It has designed and constructed by a mechanical engineer - so whilst we should stay in our areas of competency for the most part. In my case it was the mistake of a mechanical engineer. I was simply picking up the...
Hi All,
Apologies for such a delayed update (I was struck down with C19...). Two important pieces of information has now come to light.
1. Pump 2 - whilst specified as an exact duty match has a slightly different curve due to model changes in the product line (the third pump was added about 10...
Hi all, to confirm a couple of comments.
The butterfly valves on the suction side are all operational - doesn’t seem there is any obstructions.
The gate valves on the discharge side are all fully opened.
The valves that look like flow regulating valves are NRVs.
I was able to complete...
Just added a couple more of photos.
I am hoping to get testing done in the next week or so. Frustratingly the pressure guages we have on site are more discharge related & scaled 0 - 2500kPa, not useful on the suction side..
I understand the decrease in NPSHa when three pumps are running - however wont this also decrease the NPSHr as the pump will move back on curve (lower flow)?? Two pumps are operating at 49L/s, when three run its 40L/s (except the problem pump which is running at 30L/s).
at 40L/s the pump has an...
Sorry mate, while I’m sure grandstanding makes you feel important you’re way off the mark haha… it’s actually the weekend at the moment so can’t give you any more updates. I have previously mentioned what my plan on the site is.
Just for clarification (it seems you think this is a new...
Hi,
To answer your questions.
Suction manifold is 300mm
Pipe suction offtakes are 125mm (same as pump inlet)
Flows are measured via magnetic flowmeter (one for each pump)
Not sure how the system curve would help? The Three pumps are the same - From the small amount of testing i have seen it is not pump related, rather position related. Running the numbers for the NPSH - (3.3m is the required) there is more than enough avaiable ect.
When Pump 2 and either 1 or 3...
Can anyone direct me to some good resources on smart pipe layouts etc for pump stations? I'd be keen to read up and understand some of the more specific things mentioned in the thread so far?
Ill take on board the comments and run some in depth testing measuring suction pressure, discharge...
We had used a pressure gauge but it was showing the same across the site (from a suction perspective) it was a large range so i have requested a smaller gauge range so we can see if there is minor differences. Curve Below
Sorry Team
Ill chase up from pressure measurements.
The pumps are labelled as 1, 2 & 3 from right to left.
Yes there is a Short radius bend, the check valve and shutoff valve are located after the bend.
Pump 2 is the problem child - and only when all three pumps are operating. When operating...
Hello All,
I’m a little stumped the following… any able to offer any insight?
Normal Operating conditions 2x pumps in parallel. Third pump kicks in on level control. When third pump kicks in its flow/current in the middle pump (pump 2) is significantly lower.
Pump 1 & 3 = 40L/s @120A
Pump 2 =...
Thanks,
I appreciate the in depth response. This is where i was kinda of heading in my mind. Good to have it spelled out.
As this is what will likely be the beginning of a greater network I think it will be worthwhile getting my modelling skills up to scratch and develop a system model!
Hi Guys,
Hoping you can point me in the right direction of some literature to read.
Basically i have a main pump station and pipeline of 2300m (500L/s). after the first 1000m another pumping station will also be discharging into the pipeline (100L/s). I'm not really sure how this interaction...
