Troubleshooting Guide: FlashJet™ Pump

Troubleshooting Guide: FlashJet™ Pump

The Forbes Marshall FlashJet™ Pump is designed for reliable, high-efficiency recovery of flash steam and condensate. If you encounter operational issues, use the following guide to identify and resolve common problems.

This troubleshooting guide covers the following FlashJet™ Pump models:

FJP40
FJP80
FJP80X

How to Identify Your FlashJet™ Pump Model

To find your specific model number, please refer to the nameplate attached directly to the product body. Checking the nameplate ensures you are referencing the correct technical data.

Maintenance Safety Note

Isolation: Before any troubleshooting or maintenance, isolate the unit from both the supply and return lines.
Depressurize: Open the pump body drain to normalize pressure to atmospheric levels.
Temperature: Allow the unit to cool to avoid burns before handling.
Qualified Personnel: All work should be carried out by qualified personnel using appropriate tools and protective clothing.

FlashJet™ Pump Troubleshooting Guide

Failure Mode	Possible Cause	Remedy
Pump stops working	Motive supply is closed or motive line strainer is choked.	Open valves to supply motive pressure or clean the strainer.
	Condensate inlet line is closed or strainer is choked.	Open the condensate inlet valve and clean the strainer.
	Condensate discharge line is closed.	Open all discharge line valves to allow free discharge to the destination.
	Motive pressure is insufficient to overcome back pressure.	Adjust motive pressure to be 2 bar g higher than total back pressure.
	Float is punctured.	Replace the float assembly.
	Steam is leaking continuously from the exhaust line.	This indicates a leaking motive steam inlet valve; clean or replace valve internals.
	Exhaust valve is leaking.	Clean pump internals and verify/correct the setting of the valve actuator disc.
Pump overflows during discharge	The inlet check valve is leaking.	Lap the seat; if the leak persists, replace the check valve.
Pump continuously overflows	The FJP unit is undersized for the current load.	Verify rated capacity against the capacity table and install an additional unit if required.
	Inlet or motive line strainers are partially choked.	Clean the strainers and ensure all valves are fully open.
	Flash vent line is closed.	Ensure the receiver is vented to a suitable application as recommended.
	Insufficient motive pressure to achieve rated capacity.	Increase motive pressure as required based on the capacity table.
	Outlet check valve is stuck open or leaking.	Clean or replace the outlet check valve if damaged.
	Condensate return line is too small.	Ensure the return line size is equal to or greater than the pump discharge line.