Flow control of waste water stream

Hi all-

Looking for a stand alone valve/controller to regulate wastewater flow to 100gpm. would like to make it a self contained as possible without the use of analog i/o in a plc.

what i have is a treatment plant running without any plc's (all hardwire) they are now required to dischage only 100 gpm to the local sanitary authority. I have found a nice magnetic flowmeter (sparling) that will output 4-20 or 0-10. my problem is i cant locate a valve capable of scaling the signal internally without the use of a plc.

any help or advice is greatly appreciated!

Kates may have or can build what you need: http://www.wakates.com/iqvalve.asp

A simple mechanical solution would be to calculate flow based on the area of the opening and static pressure on the supply side.

I cant thik of the equation right now but GPM is a factor of pressure, viscosity, amd the flow opening area.

Presumeably you have an overflow basin of some type. So lets say you provide a discharge tank with a fixed opening/valve at the bottom. A overflow/spillway at or near the top of discharge tank would in effect regulate the pressure behind the opening at the bottom of the discharge tank. Any overflow would be returned to the overflow basin by gravity. Your entire control system would be a simple level switch to turn off the pump filling the discharge tank when it starts to overflow. No PLC, flow meters, etc.. required. In short a small water tower.

how about an orfice plate, think it would work? link---> http://www.imperialco.net/page7.html

That's a winner for me!

check this out
http://www.buerkert.de/products_data/datasheets/1067_DTS1000010865B_DE_00001.pdf

sorry it´s in german but you can see the pictures
found the english version
http://www.buerkert.de/products_data/datasheets/1067_DTS1000012063-_EN_00001.pdf

here you can checl all the different products
http://www.buerkert.com/COM/buerkert_datasheets.php

There's a category of commercial instruments known as single loop controllers that are designed to control a modulating valve.

The input signal is typically 4-20mA from a magnetic flow meter, the control algorithm is known as proportional PID control, and the output is 4-20mA.

The 1/4 DIN single loop controllers are designed for panel mounting, are run from AC power, have a couple display lines to show the process variable (actual flow) and the setpoint (100gpm).

Most if not all single loop controllers have some form of auto tuning nowadays, so that one doesn't have to fool around with tuning the loop.

We use the Honeywell UDC line, other brands are Yokogawa or Siemens.

Dan