Blocked Orifice Plate

Depending on the process it could be catastrophic. Upstream pressure could cause pipes to burst if the blockage is too great to be forced through the orifice. Downstream a lack of flow could cause cavitation in pumps (if they are part of the process) or other similar problems. More information is necessary to give a more insightful answer.

Hi,

The electric pump is on the upstream side of the orifice plate (It pushes and not pulling on the process fluid). We are using the differential pressure to calculate flow ( it,s a 3051CD Rosemount transmitter). It has not happened ( yet ! ! ). But I was wondering, if the orifice plate gets blocked by a mud, wouldn,t the transmitter give us a false DP due to the high side impuls line now been at the same pressure with the upstream side ( No pressure on downstream side ).

Dorsey,

I am more of a hydraulics person than an instrumentation person but I believe you are corrent in your assumption. Others on the board seem to be more knowledgeable about instrumentation. Good luck.

Let me rephrase that, I don't know that it would 'falsely high' since there would be a higher pressure upstream due to the blockage.

I presume you meant the effect on the transmitter,not other processes up or downstream.It all depends on the brand and type of transmitter you are using.Some of the old pneumatic ones would rupture a diaphragm and fail, but some of the new models can tolerate up to 10000 psi overload.Check the specs from the manufacturer.

If the signal was being used to control crtical flow, the valve would be totally shut,the recording chart would go off-scale, alarms would annunciate a problem,phone numbers would be dialed, people would be woken up from a good nights sleep,or midday slumber,people would scramble around like ants,with only a few knowing what to do,the rest supervising the mayhem and semi-controlled chaos.Electricity usage would see a spike at the generator due to all of the coffee pots turning on at once, profits at the utility company would surge,and the fast food joints would see a surge in business,resulting in an increase in stock prices,tires would wear out on the vehicles more rapidly due to the jack rabbit starts and stops, resulting in more tire sales, with tire companies called back laid off employees, who would now have more disposable income to spend on everything , which would bring us out of a recession.See how simple process control and economics is?-------------------------------------------------------------------------------------------------------------- HTRN---------------------------------------------------------

Segmental ???

concentric?

Coz Mud

Downstream pressure will definetely drop causing problem for the application which uses this water. A flow switch or a pressure switch will identify this problem. But up stream pressure normally will not be affected unless it is a positive displacement pump and this is the only outlet. Normally in a process plant a single water pump will cater to many applications and the pressure will be steady.

You will see more flow than the normal conditions or overflow error i think,you can watch the recorder history for a sudden change in the flow. Or you can connect to the tx with HART protocol and see what's going on with the static pressures on the high and low sensor sides.You can look for the errors if there're. Or another method; you can make some balance calculations involved with the input and output of the system and say whether there's a wrong flow or not.