Installation & Maintenance - Protectoseal

Installation & Maintenance GuidePage 29PROTECTOSEAL SERIES NO. 20TANK BLANKETING VALVE5.3. The pressure relief device is opening below its specified set point.✔ Check the opening pressure of the pressure relief device.5.4. The blanketing valve is closing too far above its set point. This would indicate thatthe pilot valve is not functioning properly.✔ Check that the #35 lower plug assembly is screwed in all the way with the mark onthe nut lining up with the mark on the pilot body.✔ Check for debris in the pilot valve.✔ Inspect the O-rings in the pilot valve.✔ Possibly the pilot valve was not reassembled properly after maintenance.5.5. The blanketing valve flow capacity is too high for the system.✔ Refer to the “User Guide” for assistance in determining flow capacity sizing.■ PROBLEM 6: The vacuum vent or other vacuum relief device opens.6.1. The blanketing valve set point is below (more negative than) the vacuum vent setpoint.✔ Check the labels of the blanketing valve and the vacuum relief device to identify theset points. The set point of one of the units may have to be changed.6.2 The blanketing valve is opening below its set point.✔ See 1.4.6.3. The vacuum vent is opening above its set point.✔ Check the opening pressure of the vacuum relief device.6.4. The blanketing valve flow capacity is not high enough for the system.✔ Refer to the “User Guide” for assistance in determining flow capacity sizing.■ PROBLEM 7: The blanketing valve cycles, repeatedly opening and closing.7.1. The blanketing valve flow capacity is too high for the system.✔ Refer to the User’s Guide for assistance in determining flow capacity sizing.7.2 **The check valve in the line between the outlet and the purge meter is not sealing.✔ Refer to the section on “Integral Purge Accessories” on page 17 for procedureson investigating the operation of the check valve. Replace the check valve if it is founddefective.NOTE:** Refers to optional equipment which may not be included with your unit.