In this guide we’ll walk you through everything there is to know about liquid 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 liquid dump valves.
Use the table of contents to skip to different sections of the learning path.
The Lever Operated Liquid Dump Valve is designed to provide emissions-free liquid level control in vessels such as heater treaters, two-phase separators, three-phase separators, and free water knockouts.
In this article, we’ll explain how to adjust the dump valve and cover some troubleshooting scenarios. We’ll also provide a detailed torque calculator to help you select the correct size.
A dump valve uses process fluid to balance upstream and downstream pressure. As part of a liquid level control system, the dump valve works with a trunnion assembly, float, and linkage rod.
Here’s how adjusting the linkage rod, lever bars, and float will affect the dump valve operation:
Ideally the angle, θ, should be zero to maximize torque. The greater θ is, the less torque is applied to the valve lever bar for both opening and closing.
The valve will either not open fully or not close fully due to the mechanical linkage or other physical impediment.
Make sure the float has full range of motion and is not being stopped short by the weld neck or any other obstruction. The best way to do this is disconnect the linkage rod and manually move the trunnion lever bar all the way up and down. If the weld neck is the obstruction, then you may need to have it cut to a shorter length.
Explanation: If the float is not able to travel its designed full range due to an obstruction, then the trunnion lever bar might not be able to move enough to fully actuate the valve.
If the valve is not fully opening, increase the distance between the two lever bars. Loosen one ball joint on the linkage rod and then move the lever bars slightly away from each other. Then re-tighten the ball joint. If the valve is not fully closing, do the same thing except move the lever bars closer to each other.
Explanation: Setting the lever bars further away from each other pushes the valve lever bar down further, causing it to close sooner. Setting the lever bars closer to each other lifts the valve lever bar up, causing it to fully open sooner.
If the float has full range of motion, change the connection points on each lever bar where the linkage rod is pinned in. Move the pin in the trunnion lever bar one hole over to increase L1 by 1?. Next, move the pin in the valve lever bar one hole over to decrease L2 by 1?. Keep doing this, one pin at a time, until it is enough to give full movement to the valve to fully open and close it.
Explanation: Increasing L1 or decreasing L2 increases the opening/closing travel of the valve compared to the up/down travel of the float inside the vessel. However, the drawback is that this will reduce the force applied to the valve from the trunnion.
Even when the float is fully submerged in the bottom liquid, it won’t move up all the way, so the valve is not opening fully.
Change the connection points on each lever bar where the linkage rod is pinned in. Move the pin in the trunnion lever bar one hole over to decrease L1 by 1". Next, move the pin in the valve lever bar one hole over to increase L2 by 1". Keep doing this, one pin at a time, until it is enough to fully open the valve.
Explanation: Decreasing L1 or increasing L2 increases the opening/closing force to the valve. However, the drawback is that this will reduce the travel range, so the risk is that you won’t have enough movement to fully open or fully close the valve.
Replace the float with a larger volume float. Use the calculator to determine what size you need.
Explanation: More volume in the float creates more displacement in the liquid, which generates more upward force on the float to help push the lever down and open the valve.
Replace the float rod with a longer one, and/or lighter one. Use the calculator to determine what length/weight will work.
Explanation: A longer rod creates more leverage, so that the displacement force on the float generates more torque transferred to the valve. A lighter rod reduces the downward force on the float.
Add weight at the end of the trunnion lever bar to counterbalance the float weight. You may need to bolt on an additional lever bar to the end of the trunnion lever bar to get enough length that the added weight will generate enough counterbalance.
Explanation: Adding weight to the trunnion lever bar increases the closing force on the valve. However, the drawback is that it also decreases the opening force, so the valve might not open fully.
The valve isn’t fully closing even though the trunnion lever bar seems to be moving upward.
Change the connection points on each lever bar where the linkage rod is pinned in. Move the pin in the trunnion lever bar one hole over to decrease L1 by 1?. Next, move the pin in the valve lever bar one hole over to increase L2 by 1?. Keep doing this, one pin at a time, until it is enough to fully close the valve.
Explanation: Decreasing L1 or increasing L2 increases the opening/closing force to the valve. However, the drawback is that this will reduce the travel range, so the risk is that you won’t have enough movement to fully open or fully close the valve.
Add weight to the float or get a larger, heavier float. Use the calculator to determine what size you need.
Explanation: A heavier float generates more downward force on the float to help pull the trunnion lever bar up and close the valve.
Replace the float rod with a longer one, and/or heavier one. Use the calculator to determine what length/weight will work.
Explanation: A longer rod creates more leverage, which generates more torque transferred to the valve. A heavier rod increases the downward force on the float which helps close the valve.
Our easy-to-use Liquid Dump Valve Torque Calculator will help you determine what size controller, float, and valve you need for your specific conditions. Note that there are two tabs—one for two-phase operation and one for three-phase operation.
Download the Torque Calculator
For further questions regarding the Lever-Operated Liquid Dump Valve or any of our other products, contact your local Kimray store or authorized distributor.
Maintaining accurate oil and water interface is vital for proper separation in upstream oil and gas production.
In a 3-phase separator, liquid level controllers allow oil and water to fill or dump from the vessel as required for each fluid individually.
In this video Kyle shows two adjustments you can make to your mechanical liquid level system to maintaining an accurate oil and water interface level.
If your float is not weighted at all, it will float on top of the oil and will not control the interface level. If left this way, as more emulsion enters the vessel, the oil pad will increase to the point that it is being dumped out through the water dump valve.
If your float is too heavy, it may not even sense the water level. The dump valve will not be able to open under these conditions. If your dump valve is never opening, this may be the case.
float too heavy
The float should be heavy enough for it to sink through the oil but buoyant enough to float on the water.
float correctly weighted
As your well matures, production fluid gravities will change, which will affect the buoyancy of the float.
You can see the interface level of your vessel in the sight glass and you can confirm it's operating as it should. It is important to regularly monitor this level so you can adjust the float or mechanical linkage as needed.
Below are the two adjustments you can make to correct this.
To get the float to sink through the oil and operate in the oil-water interface you need to weight it properly.
Without the float being weighted correctly, it will float on the lightest fluid, which is the oil, and not control the interface.
The torque and travel for both the trunnion and dump valve lever arms are adjustable by changing the position of the linkage rod on the lever arms.
As you move the linkage rod towards the fulcrum point, you will increase the valve travel or how much the valve opens but it will also decrease the torque. When you move the linkage rod connection away from the fulcrum point, you increase the torque output but decrease the valve travel.
This is a give and take between the valve torque and travel. The higher the operating pressure is the, more torque the valve will require to open against that pressure.
The fluid rate will also determine if the valve needs to open further. If the valve is not able to evacuate the fluid fast enough, the valve travel will have to be increased.
A good starting position would be in the middle of each lever arm. From here you can make small adjustments to find what works best in your conditions.
There are 3 new key trunnion hub and dump valve design features which maximize performance in products used for interface control.
There are now lever hub set screws in both the Trunnion assembly and Lever-Operated Liquid Dump Valve, which eliminates rotational play at those connections.
The trunnion assembly now has a threaded design on the float arm hub, which yields no rotational play at that connection to the shaft.
The trunnion hub and shaft designs have been updated in the lever-operated dump valve. A new shape, thicker hub cross-section, and tight-tolerance precision manufacturing has minimized rotational play in this connection to the least amount of any other solution.
