Author: Admin

A pressure relief valve (PRV) is a safety device used on pressure vessels, boilers, or integrated in process control systems to prevent damage due to excessive pressure. When a pressure exceeds a preset limit, the valve opens to relieve some of the gas, vapor, liquid, or steam, the pressure then drops to a manageable or normal value. In most scenarios, the valve will reclose or reseat so there is no downtime or interruption in the process. There are several types and classifications of pressure relief valves available in the industry, periodic testing and maintenance is mandatory for most PRV’s found in Oil & Gas, Power Generation, Chemical, and Aerospace. This maintenance and testing may occur in the field or the device may be removed for a complete overhaul in order to meet the ASME or API published codes for pressure relief devices. Proper operation is essential to prevent damage or injury to personnel.

Traditional Testing Method

A common approach to testing PRV’s is to install an analog test gauge or several gauges depending on accuracy requirements, apply pressure, and then watch the needle of the gauge to catch setpoint pressure. The technician may repeat the test several times in order to get a true baseline and record the results manually. The results from different technicians may vary and the accuracy of the test is subject to interpretation.

A Better Way to Test with a Vaetrix ETG Series Gauge

• Use the Min/Max feature to display the maximum, minimum, and live pressure readings simultaneously. The digital display clearly lets you see the maximum value that was reached during the testing process with a sample rate of 4 readings per second. Just press Reset to conduct another test.

• Every Vaetrix digital pressure gauge is provided with a NIST Traceable Certificate and Data backing the accuracy statement for peace of mind and confidence in the reading.

• One gauge rated at ±0.05% or ±0.1% full scale can replace several analog gauges that may be required depending on the test accuracy or uncertainty. Save time performing tests and reduce overall maintenance costs.

• Document the test with a press of a button. All Vaetrix ETG digital pressure gauges come standard with data logging capability to perform this test based on a 100 sample points and unlimited sessions. Just download the software and use any USB to Micro B cable to record the results digitally. The tabulated data with graph can be printed or stored digitally to meet quality assurance requirements.

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*Purchase the data management software to record up to 64,000 points and turn your gauge into a data logger with an adjustable update rate (1x per second to 24 hours).

by Jason Dewar, Vaetrix

Pressure testing is the practice of subjecting pipes or pipeline systems to pressure above operating pressure to confirm the integrity of pipes and fittings that make up the system. The concept is to pinpoint any weaknesses before something goes wrong. For most low-pressure gas lines, the preferred test medium is compressed air or nitrogen. For example, a two-inch service main may be tested at around 100 psi for 10 to 15 minutes and must hold steady pressure. Increased regulations now require that all new transmission lines, distribution lines, or service line installations be pressure tested before being placed into service.

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Retrieving Pressure Data using the Data Director App

Any Vaetrix ETG equipped with the Bluetooth option will work with the Data Director application. Data-logging sessions can be configured, started, and stopped using a phone or tablet. The interface is very easy to use and the gauge clearly indicates LOG on the LCD display.

While company policies vary on what type of device is acceptable for testing, one thing is consistent. The results must be recorded and stored in the gas company’s record system. So, whether the technician is using a pressure chart recorder, analog gauge, deadweight tester, or even a digital pressure data logger, they must ensure the results are scanned in and uploaded back in the office. This takes time and can be expensive if the test results are lost, not accepted, or have to be redone. What if there was a faster and more reliable way to view, store, and share test results in the field?

Upload the results with one button click. View and rename sessions on the phone, upload results to the phone, or take it a step further and save them to the cloud. The account is free from Google and can be set up for any business or individual Gmail account. Add testing notes using Microsoft Excel or Google Sheets, and create a secure PDF to share the file. Email a copy of the test or share a link to the file. All you need is an internet connection.

The Vaetrix ETG can store 64,000 records or 200 sessions in the gauge memory. Each pressure point is recorded with a date/time stamp from a real-time clock within the gauge.  Data is stored until you erase or delete the memory in the gauge. If you prefer to transfer the results using USB, just plug in the cable and download the Data Director software application for your PC.

Pick 0.05%, 0.1%, or 0.25% of full-scale accuracy to fit your accuracy requirements. The accuracy is based on a temperature range of 14°F to 122°F and remains constant through the pressure range selected. All ETG units come with a NIST Certificate and Data. The serial number and gauge model information is recorded on every data logging session to ensure traceability.