Metering Devices & Valves

Service valves are so basic, and we see them with such regularity that we can miss them altogether. Before I give the tips, I want to address the tech who tells the customer it was “probably the service valve” or “the caps were loose” as a plausible reason for a leak without actually making a […]

Depending on what segment of the business you are in and your location, you either work on pump-down solenoid systems all the time, or YOU HAVE NO CLUE what a liquid line solenoid is. A liquid line solenoid valve (LLSV) is just a valve that opens and closes; it has a magnetic coil. Depending on […]

I remember it like it was yesterday. It was my first day of work as a trainee at my first technician job, just a wet-behind-the-ears kid fresh out of trade school. It was a Monday morning, and the technicians and I were standing in the dusty warehouse surrounded by stacks and stacks of brand new […]

There has been much written and many jokes made about the misdiagnosis of TXV (thermostatic expansion valves), and rightly so. This article on how to diagnose TXV failure will cut straight to the point to help those of you who may still need a bit of clarification, and hopefully, we will save the lives of […]

There are many brands and styles of evaporator pressure regulating valves (EPR), but none as common as the Parker/Sporlan SORIT and ORIT valves. Photo Courtesy of Parker/Sporlan The diagram above clearly shows some of the common applications. An EPR or “hold back” valve maintains a set suction line pressure and, therefore, coil temperature. That is […]

There is a lot of misunderstanding about the HSO (hard shut-off) or “non-bleed” TXV (thermostat expansion valve) and what makes it shut off, why it exists, and how it “magically” opens. Once you understand the forces inside the valve, it is quite simple, obvious, and sadly devoid of any magic. The Three Forces  The TXV […]

Electronic expansion valves (or EEVs) are metering devices that you’ll find in a variety of modern HVAC equipment, including heat pumps, VRF units, inverter mini splits, and chillers. This valve is electronic rather than mechanical and can precisely control the flow of refrigerant into the evaporator and optimize efficiency for heating and cooling units.  Other […]

This is a quick tip from the “Expansion Valves – What Does and Doesn't Matter?” livestream on our YouTube channel featuring Joe Shearer, Matthew Taylor, and Corey Cruz. Thermostatic expansion valves (also known as TXVs or TEVs) don’t have little brains that tell them when to open or close to maintain a specific superheat. They […]

This is a quick tip from the “Expansion Valves – What Does and Doesn't Matter?” livestream on our YouTube channel featuring Joe Shearer, Matthew Taylor, and Corey Cruz. As metering devices, TXVs can adjust the size of their orifice to maintain a constant superheat. Some TXVs are set to maintain a specific superheat from the […]