FAQ


Pressure Gauges

What is the warranty on a pressure gauge?

Winters offers a 5 year warranty on pressure gauges.

There are so many gauges available. How can I choose the correct one?

Winters carries very comprehensive lines of pressure gauges to ensure we meet the requirements of all industrial markets. There are several ways for you to correctly select a pressure gauge:

1) View the selection matrix.

2) Read the Support Tools sections to get more in-depth coverage of the parts of pressure gauges.

3) Call to speak with a technical sales representative who will be able to help you pick the gauge you need and order it.

How do I specify the correct pressure ranges?

Winters recommends choosing a pressure range where the normal operating pressure will fall in the middle of the scale (i.e. choose a 0/160 psi gauge if your normal working pressure is around 80 psi). Having a higher range will also protect the gauge from pressure spikes or accidental over-pressure.

Do you oxygen clean pressure gauges?

Yes. Oxygen cleaning is highly critical when the pressure instrument is meant for use with gaseous oxygen service. If you would like a pressure gauge or instrument oxygen cleaned, please give us a call.

I see 3-2-3% accuracy for some gauges. What does this mean?

ASME specifies eight main accuracy “grades”: 4A, 3A, 2A, 1A, A, B, C, and D. Pressure gauges that have a 3-2-3% accuracy is categorized as ASME Grade B, meaning that the lower and upper 1/4 of the scale has 3% accuracy and the middle 1/2 is 2% accurate.

What is full scale accuracy?

Full scale accuracy applies to ASME Grades 4A, 3A, 2A, and 1A, so the percentage of error is uniform across the entire scale and not variable like Grades A, B, C, and D.

When should I choose stainless steel over brass wetted parts?

Stainless steel is more durable than brass, so it is important to select stainless steel when you are measuring pressure of corrosive media. Always use a material compatibility guide to make your selection or contact a Winters representative.

What are the most common connection types?

Standard thread on Winters pressure gauges is NPT (National Pipe Thread). NPT connections are standard in North America, and may also be defined further as NPT male (external threads) orNPT female (internal threads). Optional connection types are SAE, BSP, BSPT, or JIS. If you are unsure of the type of connection you need, please speak with a Winters representative.

How are pressure gauges mounted?

The mounting location is determined by the equipment and/or space. Bottom, centre back, lower back, side and in-line connections are considered direct mount. This means that the pressure gauge’s socket and wetted parts are in direct contact with the media being measured. Consider purchasing a back flange for panel mounts, or a front flange if you need the gauge to be flush mounted. U-clamps are available as an alternative to flush mounting a gauge, or if you are unable to use a front flange. If a piece of equipment produces heavy vibration, you may remote-mount a gauge.

Pressure Transmitters

What is the housing material?

Many of our transmitters come with a 304 stainless steel or 316 stainless steel housing. Others, like the LM-Series submersible transmitters, will have 316Ti stainless steel. The well service transmitter has a 316L stainless steel housing. These materials protect the transmitter more in harsh environments or aggressive media.

What is the standard output?

The standard output signal is 4-20 mA.

Is it called a “transmitter” or “transducer”?

The general difference between a transmitter and transducer is the electrical output, where a transmitter outputs signals in milliamps (mA) and a transducer outputs signals in volts (V) or millivolts per volts (mV/V).

Are transmitters susceptible to temperature?

Yes. Like all instrumentation, transmitters have an optimal operating temperature range. These ranges can go from -40F (-40C) to as high as 275F (135C). Using transmitters outside their normal operating temperatures may affect accuracy or stability.

Pressure Switches

What is standard pressure connection?

The standard pressure connection for all Winters pressure switches is 1/4″ NPT female. 1/2″ NPT male is available as an option.

What is a set point adjustment?

Pressure switches actuate at a given set point. This is set at the factory but can also be pre-set according to customers’ specifications. Winters pressure switches are field adjustable (screw type) and can therefore be easily adjusted on-site. The set point adjustment is located inside the housing to prevent tampering.

Which type of pressure switch will have the longest service life?

In general, diaphragm actuated switches will have the highest cycle life, followed by the piston type and then bellows type.

What is switch “chatter” and how does it affect service life?

Switch “chatter” is the major cause of switch contact burnout. If the deadband setting is too small, a switch will continually open and close for only minimal changes in the process input pressure. This is to be avoided as much as possible as it will shorten the life of a pressure switch.

How many types of sensing elements do Winters’ pressure switches have?

Winters utilizes two types of sensing elements: diaphragm and bellows.

Can I order switches without a cover?

Yes. Winters offers pressure switches without cover/housing or fully housed. Certain applications call for wiring to be exposed to allow for wiring, easy set point adjustments, or installation into panels. However, housing brings the advantage of covering the wires from possible industrial hazards and can be ordered as NEMA 4X, 12 or 13.

Diaphragm Seals

What is the displacement requirement of the instrument selected?

Regardless of the type of instrument, the displacement capability of the diaphragm seal must exceed the displacement requirement of the instrument. Vacuum applications or instruments that are to be in compound service (atmospheric and less than atmospheric pressure) should be reviewed with Winters.

What is the expected accuracy of this diaphragm seal and instrument?

Knowing what is expected from the instrument is essential in defining the specification. The accuracy is typically stated as the greatest inaccuracy allowable as a percentage of full scale indication. The addition of the diaphragm seal may have a compounding effect to the accuracy of the indication. Try to optimize the performance relative to the cost impact.

What is the range of process and ambient temperatures?

Choose a fill fluid that will be well within the operating temperature range to avoid vapourizing the fluid and minimize errors. Winters can provide the thermal coefficient of expansion for various fill fluids. Care should be taken in selecting compatible fill fluids when the process media is considered a strong oxidizer or is reactive with hydrocarbon-based silicones (i.e. oxygen, chlorine, fluorine).

What type of piping system is the diaphragm seal to be mounted?

Industrial piping systems can require flanged off-line, threaded off-line, and many styles of inline process connections. Care should be taken in selecting a diaphragm seal assembly that will maintain or exceed the piping systems maximum working pressure. Sanitary piping systems require specialized flange configurations and surface finishes. There are also many non-standard or custom designed configurations available.

What is a compatible material of construction?

A wide variety of exotic metal alloys and non-metallics is available. Attention should be given to the reduced pressure and temperature limitations of non-metallics. When in doubt, look at the material of the existing piping system or storage vessel. Like materials are usually available as diaphragm seal materials.

How is the diaphragm seal mounted to the instrument?

The diaphragm seal can be mounted directly to the instrument or by utilizing capillary lines to place the instrument further away from the process containment. Long capillary lines (in excess of 20’) will contribute to inaccuracies and slow response.

How and who is going to fill the instrument and diaphragm seal?

Knowledge of high-vacuum technology and filling techniques is imperative to the successful application of a diaphragm seal. An assembly that is 99% filled will never provide acceptable performance. Winters sells diaphragm seals and instrumentation that ship to customers completely filled. Winters also offers fluid filling service.

What are the common fill fluids for Winters diaphragm seals?

Glycerin-water is the standard fill fluid used in our diaphragm seals. Silicone fill fluid is used for higher temperature applications. When oxidizers are present, Halocarbon®, Fluorolube® and Krytox must be specified. Process and ambient temperatures, pressure and compatibility with the media must be considered when specifying non-standard fill fluids.

Thermometers

What is the lens material on your thermometers?

Most Winters thermometers will come with a glass lens. However, we also provide acrylic and polycarbonate lenses.

What types of thermometers do you carry?

Winters carries 5 types of thermometers: bi-metal, liquid-in-glass, remote reading (with C tube operation), RTD and solar digital. There are benefits and advantageous to each of these thermometers so it is important to know the environment and location for each application.

What are thermowells and do I need them?

Thermowells must be used on any application where the stem of the thermometer may be exposed to pressure, corrosive fluids or high velocity. Thermowells come standard with many of Winters’ thermometers. A thermowell is fitted/mounted directly into the process line and creates a closed system so that thermometers may be interchanged for calibration or repair without disturbing or closing down the process. Thermowells are available in brass or stainless steel. Other materials and flange options are available upon request.

An RTD and remote reading thermometer both measure temperature remotely. What are the differences between them?

The primary difference between these two products is the reading output: an RTD provides an electronic output signal to a display or controller which will read the signal to display the temperature. A remote reading thermometer operates manually by indicating the temperature as a result of expanding/compressing gases in its Bourdon C tube. An RTD is very accurate and provides stable operation over time, but is not suitable for high vibration or mechanical shock environments. A remote reading thermometer, however, is not subject to indicator error from ambient conditions, but is not as accurate as the RTD.

 

Accessories

Do you carry gauge snubbers?

Yes. Snubbers are vital to the service life of pressure instruments, as they lessen the damaging effects of pulsation. Winters snubbers operate to the maximum of 20,000 psi and are available in stainless steel and brass.

Heavy equipment vibration is making it difficult to capture accurate pressure readings. What can I do to alleviate this problem besides liquid filling the case?

Winters has a StabiliZR™ movement which can be fitted to most gauge internals or ordered as a complete gauge unit. The StabiliZR™ movement or StabiliZR™ series of gauges contain a dampening compound in a cap that will provide enough resistance to the pointer shaft to control needle “fluttering”.

How can I control damaging high pressures to instruments?

Overpressure is a common cause of instrument damage. Winters manufactures a variety of accessories to address this problem, including snubbers, ball valves, needle valves and over pressure protectors.

How can I control damaging high temperatures to instruments?

A cooling tower may be used. Winters’ cooling tower radiates process heat from the coil through the casing holes before the process reaches a pressure instrument. Syphons are also available to act as a cooling coil as it is installed between the instrument and process.

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