After a process sample stream is analyzed, it must be disposed of in a manner consistent with environmental regulations. Today, as in the past, it has been common practice to simply vent the sample stream to the atmosphere. As environmental regulations become more stringent, it is becoming undesirable, if not illegal, to admit these samples to the atmosphere.
For an analyzer to operate correctly, it must be calibrated and operated under the same conditions. These critical conditions are temperature, flow, and pressure, with the pressure of the measurement cell being the most critical. Venting analyzer effluent to atmosphere is not only convenient, but it also provides a very stable reference pressure for the analyzer measurement cell. In other words, the measurement cell “floats” on atmospheric pressure.
Analyzer outlet sample streams are traditionally collected into a closed vent header. This vent header either flows to atmosphere or back to the process. When atmospheric venting is not allowed, the most common disposal point is the plant flare where the analyzer sample stream is burned. However, the flare header is subject to pressure variations as high as 20 psig or more as process upsets create backpressure. When venting an analyzer into the flare collection system, the measurement cell “floats” on these varying pressures. If this condition is left unchecked these pressure fluctuations will result in significant analyzer measurement errors.
The primary function of the Parker Vent Master™ is to isolate the analyzer from fluctuating outlet pressures by controlling the pressure of the collection header (commonly referred to as the Vent Header) and pumping the effluent sample gases into the fluctuating return system.
See if a Parker Vent Master can help eliminate upset sample conditions in your applications.
For your convenience, Viking offers free consultations to assist you and your company in determining your needs. Contact us to discuss how we can help.