Are your gauges installed properly? WIKA’s FAST team of audit experts knows that all too often this isn’t the case. Improperly installed gauges can lead to premature gauge failure and prevent you from troubleshooting issues with equipment or processes. Don’t let this happen at your plant. Use these six tips for proper gauge installation.

1. Select the Right Gauge

Before you pull out a wrench, first make sure you have the right type of gauge for the application. The pressure gauge you choose must be the correct one for the:

    • Expected pressure range to be measured. The selected range should be double the operating range.
    • Process media compatibility.
    • Process temperature
    • Severe operating conditions (e.g., vibrations, pulsations, pressure spikes).

However, even if you install the gauge perfectly, you could face the same problems you had before the installation if the gauge isn’t the right one for the job.

2. Apply Force on Wrench Flats

Once you’ve chosen the correct gauge, pay attention to how you install the gauge. Rather than turning the case by hand, use an open-end wrench and apply force to the wrench flat. Applying the force through the case could damage the case connection as well as the gauge internals. Not applying sufficient torque could result in leaks.

3. Seal the Deal

Notice the type of threads on the gauge before you seal it. If the gauge has parallel threads, seal it using sealing rings, washers, or WIKA sealing rings (crush rings). If the gauge has tapered threads, additional means of sealing, such as PTFE tape, are recommended. This is standard practice for any pipe fitter because tapered threads do not provide complete sealing on their own.

4. Use a Clamp Socket or Union Nut with Straight Thread

When tapered threads are used, the installer has the luxury of adjusting the gauge even after sufficient torque has been applied. This allows for convenient orientation of the gauge face. However, with straight threads the face orientation is not adjustable once it bottoms out. For that reason, we recommend using WIKA sealing rings (crush rings) instead of flat washers. The WIKA sealing ring allows you to correctly orient the gauge after the socket has been seated on the sealing ring. You start by tightening the gauge by hand. As soon as you encounter a resistance, apply an open-end wrench to the wrench flat and continue turning the gauge. At this point you have approximately one turn left to put the gauge into the desired position.

5. Leave Space for Blow-out

For personnel safety, some gauges come with a safety pattern design consisting of a solid wall between the front of the gauge and the Bourdon tube, and a blow-out back. In the event of a pressure build-up inside the case or a catastrophic Bourdon tube rupture, all the energy and release of media will be directed to the back of the gauge, thus protecting the people reading the gauge. In order for the safety device to function properly, it is important to keep a minimum space of 1/2 inches. WIKA XSEL® process gauges come standard with integrated pegs to insure this distance when mounting the gauge against a surface.

6. Vent the Gauge Case

Some gauges come with a small valve on top of the case. Users who don’t understand the purpose of the valve are confused about why it’s included. During shipment, liquid-filled gauges can go through temperature changes that create internal pressure build-up. This can cause the gauge pointer to be off zero. When installing the gauge, open the compensation valve to allow this pressure to vent. It should then be closed again to prevent any external ingress. After you mount the gauge, set the compensating valve from CLOSE to OPEN.

A pressure gauge can do its job only if it’s installed properly. Whether you’re an operator or a maintenance technician, use these tips for proper gauge installation to make sure your gauges perform as they should. Contact WIKA’s technical support team if you have questions about properly installing gauges.



10 Responses to
  1. SIBUSISO MSANI

    We have installed a gauge on a 150mm line but it doesn’t read anything as the line flow is less that half of the pipe and doesn’t fill the pipe most of the time. The gauge is installed at the top of the pipe.

    Should we reconsider installing the gauge at the bottom?

    • Hardy Orzikowski

      Hello,

      You do not have enough flow to fill the pipe – nothing we can assist with, because even if you mount the gauge in a different location the pressure will not be accurate due to the flow level of the pipe. The option would be to the fun pipe at full flow or choose a smaller pipe diameter. Also, you cannot mount a pressure gauge upside down as it will be less accurate. You would need to be a 12 o’clock mount to mount on the bottom of the pipe, but once again it will not be accurate.

      Kind Regards,
      Hardy

  2. David

    Hi,
    Most times when I replace a pressure gauge I have difficulty to have the gauge in the correct reading position.
    When the connection is tight the reading may be upside down or to the sides.
    Any tips for this? Many Thanks

    • Hardy Orzikowski

      Hello,

      Once you put on Teflon tape if NPT piping, you do not need to tighten all the way down. You can leave a little play when attaching. Also, you could use a swivel adapter that will allow you to rotate the gauge.

      Kind Regards,
      Hardy

  3. roel sala

    Currently, I’m on a project that use a PG on very high op. temp (972F), op. press 247psig, reformate fluid.. pls advise PG model and installation suitable for this process condition. Is pig tail enough to protect the PG from this high temp?

    • Hardy Orzikowski

      Hello,

      We do not offer a gauge with that operating temperature. We do offer a 23X.50 model that will operate up to 372F, and you could use a siphon of some sort. At this temperature is this a steam application? So 2 scenarios: 1. NON STEAM – Use the model 23X.50 with a cooling adapter or, 2. STEAM – use model 23X.50 with a siphon, but not a pigtail siphon.
      Please advise.

      Kind Regards,
      Hardy

  4. John Hoffman

    Hardy, in oil and gas production ops, are diaphragm gauges superior to Bourdet tubes? In extreme heat, we seem to be over-pressurizing the Bourdet tube, and the gauge leaks. Hydrocarbon fluid (oil, water, and gas) typically in our flow lines coming from the wellhead tree. I’ve been given a research project to select the best gauge, as this is a recurring problem. We don’t want leaks. Also, our current procedure is to leave the valve open, we have a valve below, could we use a slow-open valve to open as needed, while protecting our faces from gauge blowout. Finally, say we expect well pressure to be 1,200 psi, is there a formula you recommend to size the proper gauge? Thank you.

    • Hardy Orzikowski

      John,

      First of all thank you very much for reading our blogs. I hope you’ll find these helpful. I did read your message and I believe you are addressing several issues. Let me ask you, when you mention that the gauge leaks, are you talking about the case filling that is leaking out, or are you currently using a diaphragm seal system and the transmission fluid is leaking into the process?

      Also, when you talk about diaphragm gauges, do you mean the all mechanical Sealgauge, also known as Schaeffer Gauge, or are you talking about a diaphragm seal assembly? A Sealgauge has a diaphragm sensing element that is linked with a push rod to the movement to transfer the pressure into a pointer rotation. It does not have a transmission liquid like you will find with a diaphragm seal/Bourdon tube assembly.

      As far as the valve is concerned, my colleague Jim Ledford is the real export when it comes to valves. He is also copied on this response. If you want a “slow-open” valve, I recommend to use an instrument needle valve if this suits your application. You can throttle the pressure much better than with a ball valve. The disadvantage, of course, is that you cannot tell immediately if the valve is open or closed unless you start turning the handle.

      Most importantly is to make sure you are using a safety pattern gauge with solid front design and a blow-out back. This safety design will protect the user from gauge blow-out and media release. All, the energy will be released to the back of the case and the blow-out back will be ejected in order to relieve the pressure.

      Best regards,
      Hardy

  5. BJ Janni

    If you are installing pressure gauge on both upstream and downstream of valve, what is the minimum distance apart that the PGs should be?

    • Hardy Orzikowski

      Hello,

      The gauge can be installed directly before or after the valve. There is no minimum distance the gauge needs to be mounted from the valve. The only consideration is that the gauge needs to be mounted so it does not interfere with the operation of the valve.

      One issue that comes with every opening and closing of a valve is the water hammer effect to the gauge, which can result in extreme pressure spikes. This effect is also independent of the distance between the gauge and the valve. Besides a careful and slow opening and closing of the valve, we recommend the use of an external snubber or a restrictor. A snubber or restrictor will help with pressure spikes.

      Kind Regards,
      Hardy


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