In this guide we’ll walk you through everything there is to know about weight operated dump valves.
From the basics of how it works to step-by-step repairs and troubleshooting, you’ll gain a solid foundation of knowledge on how to operate and maintain Kimray’s weight operated dump valves.
Use the table of contents to skip to different sections of the learning path.
Experiencing operational issues with your Weight Operated Dump Valve? In this video, we explain three possible reasons for this and show you how to correct them.
If your Weight Operated Dump Valve is opening and closing too quickly or not holding tight level control, this usually indicates an issue with the valve equalizing line.
Here are three things to check:
If there are sections of your equalizing line tubing that droop, liquids can collect there and affect the accuracy of your gas going to the Weight Operated Dump Valve. This is especially true in cold weather, when these liquids can freeze.
The fix for this is to run your tubing on a consistent decline all the way to the drip pot on the Weight Operated Dump Valve. This will let all the liquids drain out. Remember to drain the drip pot daily, especially in cold weather.
Your equalizing line may be tubed up too close to the back pressure regulator on your gas line. When the back pressure valve opens to release pressure from the vessel, it creates a slight difference between the actual vessel pressure and what the equalizing line is sensing close to the back pressure valve.
The fix for this is to run your Weight Operated Dump Valve equalizing line to a place on your vessel that isn't as subject to abrupt pressure changes.
Your burner valve may be pulling gas from the Weight Operated Dump Valve's equalizing line. When the burner valve opens, it sends gas into the burner to increase temperature. This can rob gas from your equalizing line and create a difference between the actual vessel pressure and what the equalizing line is sensing.
The fix for this is to tube up your equalizing line to a place where it is not subject to volume changes when the burner kicks on.
The Weight Operated Dump Valve is a product that producers use to control levels in heater treaters.
Certain conditions can cause oscillation of the weighted lever, accelerating the progressive wear on the stuffing box seal, allowing a leak to occur.
The Weight Operated Dump Valve uses equalizing gas directly from the vessel to balance the valve, which gives it the sensitivity to be able to actuate based on the small pressure changes resulting from the rising liquid head.
When this equalizing pressure becomes different than the upstream pressure in the valve, it creates an imbalance of forces on the diaphragm. This can cause oscillation of the trim, which is visible from the outside as an oscillating lever arm.
This oscillation, over time, can lead to premature wear on the shaft and seals, leading to leaks at the stuffing box connection.
The most common causes of the imbalance and oscillation are:
Understanding that these conditions can exist in a heater treater system, Kimray has designed a new adjustable stuffing box to combat the oscillation and leaks. Now you can adjust the stuffing box nut to tighten the seal on the shaft.
The new design combats the issue in two ways:
The new design is made of stainless steel for corrosion resistance and is available in optional 316 stainless steel for enhanced corrosion resistance and NACE compliance.
The seal between the two supporting bushings provides strength and stability to the shaft, eliminating any potential angular movement.
In other designs the seal is not in between the two bushings so the weight and dynamic movement of the lever and unavoidable thickness variations in the bushings can allow angular movement of the shaft.
By tightening the stuffing box nut, the packing ring is compressed, which tightens the squeeze on the Teflon sleeve, providing a low friction surface to compress and seal around the shaft. If leaks ever do occur, simply tighten the nut until the leak stops. No need to isolate the valve and remove the stuffing box to replace the seal.
With the release of the new stuffing box design, Repair Kits will include components needed for repairs on this version and all previous versions, all in one kit.
The repair kit part numbers will remain the same:
Additionally, we offer a conversion kit that can be used to replace any existing stuffing boxes, compatible with all previous versions of the weight operated dump valve:
