Water Meter Design
Water Meter Design
(OP)
I need to install a water meter in a system composed of the water tank, a pumping station providing pressure to the water main (8 inch pipe). I want to know the best place, type of water meter to install on this system. Possible locations are between tank and pump station or on the water main after the pumping station. Anyone has experience on this? Any suggestion, resources on design of water meter are welcome.
chris
chris





RE: Water Meter Design
Do you want the meter installed outside or inside a building/vault?
How accurate of a reading do you need (what is the meter's purpose)?
RE: Water Meter Design
I would like to have it as accurate as possible. But can give up on some imperfections if necessary.
chris
RE: Water Meter Design
All meters will require maintenance at some point so it need to be in a place it can be worked on.
Hydrae
RE: Water Meter Design
Also, is the meter to be used for billing purposes or as an instrument for billing to your community from a provider (as in a regional system). In this case, you should also have an airtight agreement for the provision of water, including rates, deliverability and emergencies.
KRS Services
www.krs-services.com
RE: Water Meter Design
I can state my opinion though without full justification.
If you can afford to, reduce pipe size to increase velocity, meters just love velocity for accuracy. In this reduction go ahead and install your flow run (10 or 15 times diameter upstream, 5 downstream is close, ask manufacturer of meter). How much you reduce is the question. If you have a lot of flow time below .5 feet per second then squeeze that sucker down some more if you have the head to spare.
I would use mag meter or insertion mag meter. Some would feel comfortable with other types that are less expensive if they have experience with those, (I do not), but the mag will get it done for sure.
With most meters you can get any output you want.
PUMPDESIGNER
RE: Water Meter Design
Endress+Hauser, Yokogawa, Fischer Rosemount and Foxboro all have free software for meter selection. You can lay your hands on them and they are very interesting.
DP meters have low turndowns and high inaccuracies comparitively. However, it's budget that all matters.
You can also check reverse flow with a mag (not all models)
Regards,
RE: Water Meter Design
I am trying to use the meter below. Some colleagues had used it before and seem to be satisfied. It is a turbine meter. I will probably a 8" on a 10" watermain.
Chris
RE: Water Meter Design
RE: Water Meter Design
RE: Water Meter Design
The Schlumberger/Neptune meters typically have a +/-5% accuracy. Chosing a meter in your flow range can reduce that to around +/-1.5% (so the manufacturers say). I've never compared them side by side to a mag meter.
I have used their as well as similar meters on many systems with varying results. You need to look at your flows and select a meter based upon them, not based upon the pipe size. You will more than likely have to reduce the pipe size as mentioned previously too. Schlumberger has charts outlining the pressure loss and accuracy of the various sized meters at various flows.
If your flow varies, you may need a compound meter which basically has a turbine meter for high flows and a disc meter for low flows.
If your waters have a high hardness and tend to scale, the meter will collect the scale and have to be replaced over time. That happens in my area on a regular basis. Typically the meters last 2-5 years; but, they are less expensive than say a mag meter.
Also as was mentioned, pay attention to where you locate the meter. You will have to work on it and keeping it above ground in a dry environment makes repair/replacement easier and will extend the life of the meter.
I particularly like mag meters; but, sometimes power is not available and in all reality, if you are using turbine/disc meters at the user connections, a higher accuracy main meter doesn't give you any better results. For treatment plant applications it can be different, you are basing flows on what the treatment equipment is designed for and you want higher accuracy for control purposes.