Pressure Gauges Material Selection Criteria & Design

This article is about Pressure Gauges Material Selection Criteria & Design For Pressure Measurement of Instrumentation and Control Systems as per International Codes and standards for Commercial Buildings, Plants and Refinery Projects.

Pressure Gauges Material Selection Criteria & Design

Material Receiving General Checklist for Instrumentation & Control

General Requirements

Purchase Order and Instrument specification sheet criteria shall be confirmed and compared with instrument stainless steel tags / labels and nameplates, and shipment checked for damage, prior to acceptance of the shipment
Verify that all the instruments are from technically acceptable vendors (Attachment 1)

For instrumentation purchases from manufacturers that are not listed in this standard, a request for technical evaluation, with justifications, shall be submitted in writing to the General Supervisor, Process Instrumentation Division, P&CSD. The Instrumentation Unit/PID/P&CSD will evaluate the subject instrument product for technical acceptability, and shall inform the requestor in writing of the result. Only after the instrument has been identified as technically acceptable, and the manufacturer’s facility approved by Vendor Inspection, can the purchase order be placed. These instrument products may or may not be added to the technically acceptable manufacturer’s list.
Instruments and control systems shall operate continuously under the following ambient air temperatures without any degradation of the manufacturer’s guaranteed performance:

Pressure gauges movements shall be corrosion resistant. [PIP PCCPR001, Sec.4.2.1 April 2007]
Dials on process pressure gauges shall be 4-1/2 inches (100 mm) in diameter and shall be white with black numerals. [PIP PCCPR001, Sec.4.2.2 April 2007]
Pressure gauges shall have safety glass. Plastic lenses (acrylic or polycarbonate) can only be used if they are the standard window material for gauges supplied as part of a package unit. Lenses, when used, are to be compatible with the surrounding process and ambient environments. [PIP PCCPR001, Sec.4.2.3 April 2007]
The instruments should comply with the Saudi Aramco-defined standard conditions for process flow measurement.

As a minimum, all pressure devices shall be specified with over-range protection to 1-1/2 times the maximum system operating pressure. [PIP PCCPR001 Sec 4.1.4 April 2007]
Materials selection for pressure device wetted parts shall be type 304 or 316 stainless steel with TFE gaskets, unless other materials are required by process. [PIP PCCPR001 Sec 4.1.7, April 2007]
Pigtails or siphons shall be specified in steam and other high-temperature condensable vapor services. “siphons shall also be used for process fluids with a temperature over 250°C (480°F) when the gauge is above the tap connection.” [PIP PCCPR001 Sec 4.2.7]
Standard ranges shall be selected such that the normal operating pressure falls between 30% and 70% of the scale range.
Gauges supplied by vendors as part of other pneumatic devices such as current to pneumatic converters, instrument air supply regulators, valve positioners, piston actuators, similar devices shall be vendor standard unless otherwise specified.

International Codes and Standards for Pressure Gauges Material

1. Flow Nozzle Material Selection Criteria Design & Flow Measurement
2. Venturi Tube Material Selection Criteria Design & Flow Measurement

3. SAES-J-002 -Technically acceptable instruments, 23 June 2008
4. SAES-J-003 – Instrumentation Basic Design, 16 January 2008
5. SAES-J-200 – Pressure, 18 May 2008
6. PIP PCCPR001 – Pressure Measurement Criteria, April 2007

1. Attachment 1: Technically Acceptable Instruments, SAES-J-002