Archive: Aug 2020
Q&A: Superior Protection for Pumps and Compressors – Why Axial Flow Check Valves Are Your Best ChoiceLeave a Comment
Axial Flow Check Valves are used in a wide range of pumps and compressors in a vast array of industries. DFT® hosted a webinar on this subject which outlines the differences between check valves used in their applications, as well as the advantages or disadvantages that each one presents.
Here at DFT®, we frequently field questions regarding this topic. So we are sharing a few common questions that came in from the webinar and were answered by host Arie Bregman.
Q: What are the typical installed cost differentials between swing check valves and axial check valves?
A: Swing check valves are usually less expensive when you initially buy them, but the lifetime cost to own an Axial Flow design valve that is properly sized for the application will always cost you a lot less money over the lifetime of the valve. Swing check valves cannot be sized for low flow applications, so they will wear out and fail causing additional maintenance costs and system shutdowns. The cost to take a prematurely failed valve out and either service or replace it far exceeds the cost differential to get the right valve up front.
Q: What type of check would you use in gas service with intermittent liquids? After compressor?
Q: Can Axial Flow check valves be used in very viscous flow?
A: Yes, however depending on the viscosity and the min/normal/max flow conditions, other internal modifications may have to be considered like higher cracking pressure springs.
Q: How would you compare CV of a swing, dual plate, and Axial Flow check valves?
A: The differences in head loss between Axial Flow and Swing checks is a function of the Cv of the specific valves you are looking at – head loss must be calculated on a case by case basis. There will usually be a slightly higher head loss for the Axial Flow versus a Swing check, but in many cases, this is not consequential. In cases where pressure loss is a very important piping design consideration, the Axial Flow check valve can be engineered with lower cracking pressure springs and low friction coatings to reduce the amount of energy required to open the valve.
Q: Do you offer a sizing calculator for check valve selection?
A: DFT® does offer sizing services through our Regional Sales Managers or our Inside Sales team. We will be rolling out a new version of our sizing and configurator program very shortly to our Tier 1 distributors. For more information please use the following link to contact someone in your area: https://www.dft-valves.com/check-valves-territory-map/
Other relevant resources include: