Thanks for the question - I'm glad to help clarify!
I recently saw an article from an equipment manufacturer with a very generic statement about how back pressure regulators, valveless expansion systems and other types of pressure controls that are tied into an automation system are particularly prone to failure. Unfortunately, this type of misleading and irresponsible generalization is all too common in the cannabis industry today.
As with most equipment, generalized comments about components or portions of a piece equipment are not accurate or representative. You must get into the details before you can make an assessment about the component's ability to perform in service. A common example is a comment like "stuff made in China is junk". A general statement like this is simply not true - some cheaply made items from China will not last very long, however there are many high quality components manufactured in China that will perform as good or better than their US counterparts. The devil is in the details!
There are thousands of components that can be utilized in an extraction system, but since your question focuses on valves let's dig into the details on those:
Pressure regulators and needle valves - two types of pressure regulation valves are commonly found on extraction systems: Back Pressure Regulators and Pressure regulators. BPR's are most commonly used as relief valves, but are also used to maintain a constant back pressure in extraction vessels and also in cascading separators. Pressure regulators are commonly used in control air systems, but not commonly found in the CO2 portion of an extraction system. Regardless of the type or quality of regulator, any regulator used to control decompression in an extraction application will have the same problem -
they will clog due to the extracted oil precipitating out in the valve internals. This issue isn't restricted to pressure regulators, as needle valves, throttle valves, and any other kind of valve will always have the same problem. It is important to note that the quality of the valve has not bearing on this issue. It is simply the wrong tool for the job.
Automated Valveless Expansion systems inherently do not clog because there are no valve internals to be affected. Automated Valveless Expansion provides a stable pressure platform that can adjust to varying environmental conditions such as line voltage, ambient temperature, heat transfer changes due to vessels filling up with extract, etc.
Manually operated systems, especially those with manually operated needle valves, will not automatically compensate for these changes which
can cause flooded separators or allow the liquid pump to run dry – both requiring significant downtime and maintenance costs.
Solenoid valves - Solenoid valves were invented in 1910 and are widely used in industrial applications, including highly critical applications such as nuclear power plants, oil drilling platforms and aerospace applications. As you might expect, there are cheap solenoid valves and there are high quality solenoid valves.
Manufacturers of automated platforms with experience will have a track record of success with a particular solenoid valve. First time automation won’t have the experience and can suffer failures.
Pneumatic valves – air operated valves are very common on CO2 extraction system. It is a common misperception that air operated valves will fail faster than manually operated valves. Regardless of the operation mechanism the construction of the valve is exactly the same!
A final thought on automation "failures": It is common for operators to identify any kind of notification as an "error" or a system "failure". Notification signals are part of the automation safeguards to notify the operator when the system experienced a condition outside of the normal operating parameters, not just a failure. A great example is notification that the CO2 supply bottles are empty – it isn’t a failure of the system, however the system will not operate properly unless the CO2 bottles are changed. The benefit of the automated notifications is that the operator doesn’t have to visually monitor the system or even be in the same building – they can be notified remotely if there is an issue that needs to be resolved!