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Don’t Drown With Drain Valves

drain valve kit

Sometimes the smallest things can have a big impact on the overall process. One little component can be the difference between operation as normal and a complete process shutdown. Components like the drain valve can play a huge role in your system’s health and the production process’s efficiency.

A small valve responsible for controlling and regulating the removal of condensate can save you thousands of dollars in downtime and repairs. By properly disposing of the water the drains protect your internal equipment from rust and premature decay. The equipment necessary for this job is condensate drains, an often overlooked aspect of compressed air systems.

Condensate drain valves remove condensate separated in centrifugal separators, air receivers, refrigerated dryers and filters from the compressed air system. They are therefore indispensable components for efficient compressed air treatment and disruption-free compressed air supply.

No matter how much you spend on your compressed air system, the condensate drain is going to be the least glamorous, yet crucial part of your system. No matter how many bells and whistles you add to your compressor, if you don’t take the time to properly size and pick your condensate drain, you will be left with nothing but headaches and lighter pockets.


What Is A Drain Valve?

In order to understand the best choice of drain valve for your system we need to acknowledge the basics first. What is the baseline for being a drain valve? Are there specific components that make it a drain valve and not just a valve?

A drain valve is made up of a stem and a hollow cylindrical body. The stem runs parallel to the hollow section of the body. When the stem is open, liquid or gas travels through the hollow area of the body. The stem closes the passage through the body when it is rotated and prevents the liquid or gas from leaving.

The stem of certain drain valve designs prevents the flow, whereas the stem of others is employed to raise or lower a flow-blocking gate. Depending on the design, this gate might be in the shape of a disk or a ball. Design does impact the process so depending on the type of drain that you need will determine the shape.


Why Do I Need A Drain Valve

In its natural state, air can hold a substantial amount of water vapor. The function of creating compressed air significantly reduces the vapor-holding capacity. The compression process forces water molecules to clump together and form condensation. The effect is similar to a rainstorm inside the tank.

Drain valves can and should be found on an intercooler, aftercooler, filter, dryer, receiver, drip leg, or at point of use. When you boil it down, there are three main types of drains for compressed air systems:  

  • No air waste 
  • timer operated
  • none (yes that is a drain choice).


When these drains fail to remove all of the condensate that has collected, it will leave oil and water behind that can affect filter efficiency causing carry over into the system allowing freeze-up in the winter. This can happen from not using the ideal drain for your compressed system or not having enough in place. 

When it comes to multiple stage compressors,  moisture carry over from the intercooler may allow liquid into the next stage causing premature wear and possibly a catastrophic failure. So just more reason to have drain valves in place to prevent problems down the road.

Using an air compressor auto drain system has several benefits, including:

Prevents Damage to Equipment

Accumulated condensate can cause corrosion, rust, and other damage to the equipment, reducing its lifespan. The auto drain system ensures that the condensate is removed from the system, preventing damage to the equipment.

Improves Air Quality 

Condensate in the compressed air system can cause contamination and affect the quality of the air. The auto drain system removes the condensation, improving the air quality.

Reduces Maintenance Costs

Regular maintenance of the compressed air system can be costly. The auto drain system reduces the need for frequent maintenance by removing the condensate regularly.


Types of Drain Valves

With a little more understanding of drain valves let’s take a look at the main types you will see out in the field. There are 3 different set ups that you might run into out in the field, so let’s discuss each one in more detail.

No Drain

Yes, no drain valve is an option that some people choose to use. Whether that be not to install a drain at all, not repair a failed drain, or install a manual drain, the outcome will be the same and falls into this category.

This type of drain is something that technicians run into all the time. But it is not recommended in the slightest. Going off the assumption that you are using a manual drain valve, rather than having nothing in place, you would need to manually eject water on every drain valve after each shift. That seems a little unrealistic.

Especially when you realize that the amount of condensation being produced is going to be irregular; load and season have a direct relationship with the amount of condensate in the air. Running more during hot and humid months is going to create a lot more moisture than low runtimes during the drier winter months. And you expect us to believe you are going to keep track of that with all of your drains, highly unlikely for anyone.


Timer Operated Drain

Operating on a timer is a much more reliable and popular option than manual drain valves (we aren’t going to acknowledge no drain because that should and will not be an option for your system). Timer Operated Drains are easy to install, cheap to purchase, and usually quite reliable if installed with a strainer on the inlet.

As a standard component on many small refrigerated dryers, these drains come with an adjustable on-time and interval between drain events. They are also pretty easy to perform maintenance on: simply press the “test” button, make sure it’s plugged in, and clean the inlet strainer. That is about as simple as you can get with maintenance. 

As nice as this solution seems, except for some very special applications, timer operated drains should be considered a quick fix only. These drains can run into similar issues as manual drain valves, with moisture not completely clearing, remaining open for too long and wasting compressed air. This excess condensate can contain oil particles that can emulsify and completely prevent any more condensate from being separated and ejected.


No Waste Drain

Probably the broadest category of condensate drain valves, no-waste drains will eject the collected condensate without also blowing compressed air, but will also automatically keep up with changes in the system. Due to the wide range of models these drains can have different models for the same result.

A float drain can be considered no-waste, in fact they can be considered a good choice for many filter applications. Filter bowl floats seem to be more reliable than they used to be. No Waste drains will very rarely be identified using that descriptor because it doesn’t really clarify the specific drain. Instead it will be an assumption that your float drain is going to be no waste.

Newer models will come with a built-in particulate screen to prevent small particles from getting stuck under the seat; however, the use of cleaner piping, like copper and aluminum, becoming more prevalent has helped this drain type’s reliability.

Mechanical Float Drains may be some very old designs, but they are incredibly reliable, especially due to the fact that they can be rebuilt repeatedly. Rather than needing to replace the whole unit when one part fails like some more modern solutions, you trade convenience for consistency (this is a very negatable difference and it comes down to personal preference). 

Whether they are a modern small electronic drain or an older mechanical float, you will get consistent reliability. They will still require maintenance and an annual float replacement, but those are the only recurring costs, making it a relatively inexpensive investment.

The final type of drain is a hybrid combination of the previous drain types. By combining aspects from each filter, a float mechanism that triggers either an electronic solenoid or pneumatic piston that will open the valve. Electronic solenoid’s will inherently lose less air when removing condensate as they close before any air is lost.

Condensate Drain Valve Models

There may only be 3 “different” types of drain valves, but the market will tell you that there are a lot more than 3 options available. Individual drains can be a combination of the different types of drain valves in order to get as much of the condensate out as reliably as possible. With all these options they are each going to have their individual strengths and weaknesses, your application will determine what drains are best.


Electronic Timed Drain Valve

The simplicity and convenience of these drains make them one of the most popular auto drains available. With an electronic timer that is set to automatically open and shut at a predetermined interval to dispose of the collected condensate and debris particles.

Adjusting the interval that the valve stays open allows this equipment to be used in a wide range of compressed air applications. Adjusting the interval will allow you to adjust to demand or adapt to the environment as temperatures and moisture levels vary throughout the seasons. 



Zero Loss Drain Valve

With the goal of completely automatic moisture and debris removal, zero-loss drains are designed to do exactly that, and you guessed it, lose zero compressed air. A combination of solenoid valves and electronic sensors ensure the consistent, efficient, and effective removal of condensate and particulates. With these drains  the discharge process is entirely automatic and leak-free.


Motorized Ball Valve Drain

Through the use of a motorized ball valve that opens and closes the drain valve, providing an accurate and consistent discharge process. This makes the motorized ball valve drain an ideal solution for large compressed air systems requiring high precision and control in their condensate removal. 

Not only are these drains highly accurate, they are incredibly durable as well and can be used in harsh industrial environments. The accuracy alone makes these drains one of the best options available for your system, and then when you add in the durability there are few competitors. 


Timer Controlled Solenoid Drain Valve

With a similar operating method to the electronic timed drains, these drains use intervals to predetermine when the solenoid valve will open and close the drain valve.  This particular style of drain valves is most suitable for air systems that require a good deal of accuracy and manipulation.


Manual Drain Valve

The last on the list and the last option for your compressed air system is a manual drain valve. The name says it all, you are going to need someone to operate the valve every time you want to discharge condensate and debris. You should not have this on any machine that needs consistent clean air output.

Another way to look at this is if you cannot move the compressor around, as in a small, transportable pneumatic compressor. Compressors like this capitalize on tasks or activities that have smaller, inconsistent compressed air demands. Machines like this do not use enough air during their operation for the amount of condensate that forms to be considered a problem, as long as you remember to empty it out between uses.


Additional Considerations

When it comes to choosing your own drain valve, take your time and don’t jump on the first possible solution you see. It’s easier to take more time now to get the exact right equipment for your system. If you rush through this seemingly meaningless step, you will be regretting that decision in due time when that condensate build up starts ruining the system from the inside.

Consider your options and your process when you are looking for a drain valve to upgrade your system or complement the new equipment being put in. Picking the right type of drain can save you a lot of money in the long run. If you leave drains stuck open you will be adding unnecessary costs to your energy bill. If you need a visual, imagine money blowing out of the valve rather than compressed air.

One of the big choices you will have to make is between electronic, timer, and manual methods of removal. This simple decision can affect your system for years to come, but as long as you don’t go with the manual option where you need to remember to dispel the condensate after every usage. Automatic drain valves are going to make your life easier and your system more controlled.

Deciding between automatic drain valves can be difficult due to their similar operation methods. It is easier said than done to distinguish between these types of drain valves. Rather than focus on the regulation method, you would benefit more from understanding the valves in place and the benefits they would have for your system. It is more important to go with the correct option rather than the easy or cheap one. 

Drain Valves are an investment, not an accessory. Common rhetoric may make you believe otherwise but if you have no, broken, or manual drain valve in your system and are experiencing problems with condensate build up, there might be a correlation. 


Unbeatable Support

If you are unsure of which drain your system needs, we have experienced sales and service technicians who are able and willing to help. Simply give us a call or text and we will be there as soon as we can.

If you want to learn more from us head over to Warthog U


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