Thanks again to Fritz Rochester for taking us in the field to see how he uses the Testo 330 to check for a cracked heat exchanger and a Testo 435 to check for efficiencies in the field.

The Testo 330 and Testo 435 are available at Stromquist & Company for customers located in Georgia or Florida. If you are in another part of the country, click here to locate one of our affiliates at Controls Group North America.

Gate valves are rather simple valves that should be used as only open/close valves. Media such as steam going through the gate of the valve not fully open will cause a restriction through the valve thus increasing the velocity of the steam going through the valve which will eventually cut through the valve’s “gate” and render the valve useless.

Gate valves are classified as a rising stem or a non-rising stem valve. A rising stem gate valve will give the plant operator visual reference if the valve is open or closed.

Gate valves generally are threaded or flanged and are manufactured in bronze, stainless, iron, and a variety of other metals and pressure ratings.

As with any mechanical valve, careful consideration of application should be exercised on selecting the proper valve.

Once again Thank You Process Technology for the excellent video.

Many thanks to Fritz Rochester, Rochester Heating and Air for this great video on How to troubleshoot a Gas fired furnace. Fritz intended this video for licensed HVAC contractors. Controltrends agrees with Fritz that his techniques should only be performed by licensed HVAC professionals.

Check valves are one of the most basic but important valves in a water or steam system. The most common check valves are Ball Check Valves, Swing Check Valves, and Lift Check Valves.

Although different in design these valves are generally designed to allow fluid flow in only one direction.

The Ball Check design closes off fluid flow via a spherical ball that can be spring loaded or non-spring loaded. Fluid Flow through the valve will move the ball off the seat allowing continuous flow. When flow stops a spring (if spring loaded) will push the ball to a closed position not allowing back flow through the check valve. In the case of a non-spring loaded ball check valve the fluid back pressure will push the ball back against the seat to a closed position.

The Swing Check valve design features a gate that is attached to a pivot lever that allows the opening of the valve with flow present. Any back flow from the downstream side of the check valve will force the closure of the gate.

The Lift Check design incorporates the use of a disc that allows the disc to lift upward when positive pressure from the inlet flow is present. When inlet pressure is removed or if downstream pressure is higher than the inlet flow pressure the disc via a disc guide is lowered down to the valve’s seat stopping a reverse flow situation.

Because of varying media characteristics, including type of media like steam, air, water, and oil along with media temperatures and pressures, care must be taken in selecting the proper check valve that best meets service conditions.

Look for upcoming videos on other types of mechanical valves and I would like to thank Process Technology for their excellant videos on this subject.

For all your control needs call Stromquist and Company in Atlanta at 1-800-241-9471 or in Florida at 1-800-678-7838. If you are in another location please call use and we can get you in touch with or CGNA partners in your area.

Before you assume it’s a lost cause, follow a  few troubleshooting tips for direct-acting solenoid valves.  If doing these things doesn’t help, call Stromquist to order a new one!

Problem:  Valve will not operate when valve circuit is energized

Possible Cause: Low voltage or no voltage to coil.  Possible Solution: Check voltage at coil; it should be at least 85% of nameplate rating.

Possible Cause:  Burned out coil.  Possible Solution: See “Coil Failure” below.

Possible Cause: Foreign matter jamming core in core tube. Possible Solution: Clean valve; install strainer close to valve inlet.

Possible Cause: Binding core or damaged core tube. Possible Solution: Replace valve.

Possible Cause:  Excessive fluid pressure. Possible Solution: Reduce pressure to valve nameplate pressure rating or install suitable valve.

Problem: Valve will not close or shift when valve circuit is de-energized

Possible Cause: Coil not de-energized. Possible Solution: Check electrical control circuit.

Possible Cause: Foreign matter jamming core in core tube. Possible Solution: Clean valve; install strainer close to valve inlet.

Possible Cause: Damaged disc or seat causing internal leakage. Possible Solution: Replace with new parts.

Possible Cause: Binding core or damaged core tube. Possible Solution: Replace with new parts.

Possible Cause: Damaged spring. Possible Solution: Replace with new spring; never elongate or shorten spring.

Problem:  Coil Failure

Possible Cause: Overvoltage. Possible Solution: Check voltage at coil; voltage must conform to nameplate rating.

Possible Cause: Damaged core or core tube causing inrush current to be drawn continuously. Possible Solution: Check for damaged core, core tube or spring. Check for scale or foreign matter on the core or inside the core tube.

Possible Cause: Foreign matter jamming the core in core tube and causing inrush current to be drawn continuously. Possible Solution: Clean thoroughly and replace any damaged parts.

Possible Cause: Excessive fluid pressure causing inrush current to be drawn continuously. Possible Solution: Reduce pressure or install suitable valve.

Possible Cause: Excessive ambient or fluid temperature. Possible Solution: Class A coils are limited to ambient temps of 77 degrees F. For temps up to 167 F, use Class F coils; for temps up to 212 F, use Class H.

Possible Cause: Missing solenoid parts. Possible Solution: Install missing solenoid housing and other metal parts or properly install incorrectly assembled metal parts. The housing and other metal parts form part of the magnetic circuit and are required to provide impedance needed to limit current draw.

Possible Cause: Moisture inside solenoid enclosure. Possible Solution: Waterproof the entrance conduit to prevent entry of moisture. If valve is mounted outdoors, check to see that enclosure is weatherproof and that gaskets are in good condition; use appropriate sealant when required. If general-purpose enclosure is used in a damp or humid atmosphere, use watertight, molded coils.

Anthony, you asked for it and you got it !Have a controls question email it to eric@stromquist.com. If we cannot answer it we will find someone who can. Thanks to Affiliated Steam for helping us answer Anthony’s question

Real nice video on rebuilding a Johnson Controls pneumatic valve. Stromquist and Company has Johnson pneumatic valve repair parts in stock. Give us a call in our Florida or Georiga branches for your pneumatic valve repair parts.

For those who aren’t too familiar with solenoid valves and their function, let’s start with the basics.  A solenoid valve is an electro-mechanical device that when energized or de-energized either opens or closes a valve orifice.  It is designed to control the flow of air, water, oil, gas or steam.  Here’s some handy terminology that is helpful in understanding solenoid valves:

De-energized: Electrical current is not applied to the solenoid valve.

Energized: Electrical current is applied to the solenoid valve.

Normally Closed: Valve is in the closed position when de-energized.

Normally Open: Valve is in the open position when de-energized.

Pressure (psi): Force exerted by an object over a specific area.

Flow: Continuous movement of a media in a specific direction.

Maximum Operating Pressure Differential (M.O.P.D.): The difference in pressure between the inlet and the outlet sides of the valve, against which the valve can safely operate. If the valve outlet pressure is unknown, be conservative and regard the supply pressure as the M.O.P.D.

Minimum Operating Pressure Differential: The pressure required to open a valve and keep it open.

If you need to order a solenoid valve and don’t have an existing part number, there are a few things you need to know to make sure you get the right one for your application:

Type of media:  air, water, steam, gas, or oil

Valve body: bronze or stainless steel

Voltage:  A/C or D/C voltage requirement

Electrical operation: normally open or normally closed

Valve size: pipe size or flow requirements

Valve line pressures:  inlet and outlet pressures

Operating temperatures: maximum operating temp

Valve type: 2 way, 3 way, or 4 way

Check back soon to get some solenoid valve troubleshooting tips.

Excellent video for those domestic boiler installations. Stromquist and Company have the parts you need to keep those boilers running properly. Give us a call at 1-800-241-9471