7EA-Dual Fuel--Liquid Fuel Purge 20PL-4 Valve


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we have 7EA dual fuel DLN1.0 machine. In the line of secondary nozzle purge we have 20PL-2 & 20PL-4 with a orifice bypass is present. Could someone please explain the functionality of 20PL-4 & loop with a orifice over it? Nothing was written about it in control specification document.

Have you looked in the Operation and Maintenance Manual System Description section for Fuel Purge and/or Liquid Fuel to see if there's anything written there about the equipment?

Can you post a scanned image of the Liquid Fuel Purge P&ID to a webhosting site (such as tinypic.com) and then post a link to the image here on control.com? That way we could see the P&ID and provide more information.

Also, quite frequently the NOTES section of P&IDs also contains some very useful information to help in understanding systems and configuration.

20PL-4 is usually a solenoid operator, that controls the position of a pneumatically-operated valve with a designation like VP-nn, or something similar, which actually controls the purge air flow (in this case).

Without being able to see the P&ID it's very difficult to say too much.