Is Hydraulic Pump Intake Line Isolation a Good or Bad Idea?

You may wonder if installing a pump intake isolation valve on your hydraulic machine would be a good idea, and if so, would the ball or butterfly type work best for you? An explanation of the advantages and disadvantages may help you make up your mind.


Disadvantages of Strainers and Filters

You may wonder how a pump intake isolation valve can work better than the systems that have a suction strainer and depth filter. Traditionally, suction strainers and depth filters may be installed in piston pumps or motors. This provides some benefit, as it can enhance protection against contamination. The strainers also could prevent pump gripping. What is more, the depth filters can usually catch debris throughout the substances passing through the pump. Some strainers and filters used together also seem to withstand high pressures in pumps capable of up to 10,000 psi.

Strainers and filters are not always without disadvantages, however. For instance, they sometimes require costlier maintenance and replacement. In certain cases, the resistance to large foreign objects may not be enough. They also may not always remove some of the tiny particles small enough to fit through the strainers or filters. What is more, some filtration and straining systems can increase the wear and tear on the pump system they are supposed to protect.

Because of disadvantages with using piston pumps and motors, you may instead contemplate the use of a pump intake isolation valve. In the process, you may want to ponder two primary choices: the ball valve or the butterfly valve. You may not realize that you may have a third option, which would be to not install an isolation valve at all? You are advised to not take this decision lightly, no matter what you decide is best in your scenario.


Pump Intake Line Turbulence

One of the primary considerations when setting up a pump system is pump intake line turbulence. Any unsteady substance flow in your system could cause pump instability, which possibly could result in equipment breakdowns. Too much turbulence in your pumping systems could also result in clogs or pipe bursts. The amount of turbulence that can occur might depend on the type of valve used as well as the diameters of your pumps.

If you want to maximize the oil flow, you may prefer to use the ball valve because it allows for the full use of the opening through which the oil travels. A ball valve may not cause as much turbulence as the butterfly valve would. On the other hand, a reason for butterfly valve turbulence may relate to unguided disc movement, depending on the features of your overall system.

One reason you may want to avoid turbulence is because it can cause gaseous cavitation. This takes place as the air bubbles are exposed to pump outlet pressure after which time these air bubbles collapse. If you want to avoid this problem, you probably would want to install ball valves instead of the butterfly ones.

However, if you require ball valves between 4-6 inches in diameter you may experience one disadvantage as they often cost more and usually take up more space in length than the butterfly ones. This could especially cause problems if using a portable unit in a small space. Therefore, butterfly valves may be used instead.

Butterfly valves are sometimes preferred in small spaces. This often is the case when you have a setup with large hydraulic excavators that have multiple pipes attached to a large tank. This system usually has the wider intake lines, which take up room that otherwise could provide a place for ball valves.


Installation and Operation Woes of a Hydraulic Pump

A third option to adding an intake line isolation valve, or the butterfly or ball valve is if you find that you do not have much room to install your valves the way you want, you might want to consider not adding an isolation line at all. But “how in the world am I able to change out the pump with no isolation valve present?”

One answer to this is that a correct setup would cause the oil to pump out of the tank using a filter cart if a catastrophic pump failure does occur. It would then flow into clean collection containers or a drum. If this takes place, the tank should be thoroughly cleaned, and this is when you could change out the pump as well as the oil. If the oil is still usable, you can pump it back into the tank.

Not installing an intake line insolation valve has three benefits:

  1. You can save money for each pumping cycle performed.
  2. Not as much distance between the take and pump is needed.
  3. You don’t have to worry about starting the pump with the valve closed.

Not adding an isolation valve may seem like an advantageous plan in theory. After all, less parts means less room required to operate your equipment. However, you may find inconvenient the time it may require for maintenance, or you might not have 10-20 free oil collection drums. It may not be practical for you to perhaps pump out thousands of gallons of oil from a tank, if you work with larger amounts.

An alternative way to operate your pump without an isolation valve is to attach a vacuum device onto the reservoir. It may be a good idea to add proximity switches if you do have an intake-line isolation valve to prevent the pump from starting while one or more valves are closed.

You have additional factors to consider if deciding whether or not you should use a pump intake isolation valve and choosing what kind of valve would be best if you do decide you want to intake an isolation valve.


Setup Considerations for Hydraulic Pump Systems

The amount of available space you have for turning your hydraulic system on and off is important for choosing for or against an isolation valve. The ball valves seem to be useful for a quick shutoff and usually only require a 90-degree shutoff turn versus up to 360 degrees like alternate types of valves. The ball valve may allow for better flow control through pipes larger in diameter, especially if you have ones that are two or three feet in diameter or more.

Ball valves also seem to offer secure closures even after long stretches of time during which they may not have been used. Therefore, they may be incorporated into numerous applications instead of gates normally used in low-pressure drops or globe valves used for regulating flow. Ball valves also can provide a tighter valve closure than the rotating disc of butterfly valves.

The tight seal along with fast shutoff may be why you would choose to use the ball valve. However, it may not always be that simple. You sometimes need more control over the speed and/or amount of the flow which would support using the butterfly or another type of valve. If the need for controlling the amount or speed of flow is more important than quick shutoff, the butterfly valve may be the right solution. However, it also may not withstand as much pressure as the ball or other types of valves.

Temperatures in which your pump system will be used should also be considered. Different isolation intake valves have unique capabilities depending on the materials used to construct them. In most cases, they are made of cast iron, which can withstand hundreds or sometimes even thousands of degrees above zero. Most also can resist below-zero temperatures as well. Either way, the amount of heat or cold it can handle should relate to where you set up your hydraulic system.

The distance between your source and destination of oil is another consideration. In the case of not installing an isolation valve, it may be ideal if your source is right next to your destination. If indoors, it may also work best if where you plan to send the substance in the same room or close to it.

If you plan to send oil to a good distance away from the source, you may need more control on the flow. In this case, the intake isolation valve may be necessary. You may even need several of them depending on how far away the destination is. You might need isolation valves is if you plan to send your oil up or down several stories.


In summary, not having an isolation intake valve may be a more economical solution depending on if your source is close to your destination. But always make sure you are aware of the need for maintenance that operating a pump without an isolation intake valve may require. 

Source
https://www.flowcontrolnetwork.com/what-is-the-difference-between-full-port-full-bore-valves-standard-port-valves/
https://medium.com/@uvml/lets-talk-about-ball-valve-and-butterfly-valves-dbcbc1bf5aa9
http://www.insanehydraulics.com/letstalk/suction.html