Pressure Gages

IPE Engineering Practice IPE-EP-12-1-19

Document number: IPE-EP-12-1-19 · Section: 12 — Instruments and Controls

SCOPE

Indicating pressure gauges shall be supplied in strict accordance with EP 12–1–19 DS, this Practice, and the referenced standards and publications.
Any deviation from this Practice must be approved by the procedure described in EP 1–1–3 .
A revision bar indicates all changes made to this Revision.

2.0 REFERENCES

The following codes and standards shall be considered as part of this Practice. All documents shall be the latest editions in force on the date of issuance of this Practice.

STANDARDS AND PUBLICATIONS

IPE Engineering Practices
EP 1–1–3 Deviations to IPE Engineering Practices EP 12–1–2 Supplemental Requirements for Control Systems EP 12–1–19 DS Pressure Gauges Data Sheet
ASME
B 1.20.1 Pipe Threads General Purpose (Inch) B 40.1 Gauges - Pressure Indicating Dial Type - Elastic Element

DEFINITIONS

Manufacturer - The recipient of a direct or indirect purchase order for materials and/or equipment. In this context, a direct order is one issued to a manufacturer by a contractor or the Owner. An indirect order is one issued to a manufacturer by a vendor (recipient of a direct order) for materials, fabricated components, or subassemblies.
Owner - Inflection Point Engineering, LLC .
Owner’s Engineer - A Inflection Point Engineering, LLC appointed engineer.

4.0

4.1

4.1.1

4.1.2

4.1.3

4.2

PROCESS PRESSURE GAUGES

General

Process gauges shall conform to the requirements of ASME B40.1, Class 2A unless otherwise specified and approved by the Owners Engineer.

Pipe threads shall be tapered and shall conform to ASME B1.20.1.

Design and materials not specified shall be in accordance with the manufacturer’s standards suitable for the operating and design conditions specified on the Pressure Gauge Data Sheet EP 12-1-19 DS.

Cases and Rings

Process gauge cases shall be phenolic weather proof construction unless otherwise specified by the Owners Engineer.
All pressure gauges shall have safety type cases with a solid front and a blowout back or disc. Gauge lens shall be shatterproof.
Surface mounted gauges shall be provided with threaded removable bezel rings. Flush mounted gauges shall be provided with bezel rings which are hinged for easy opening with the gauge in position. The mounting holes shall be of the Manufacturer’s standard design.
Process Connections

Connections shall be located on the bottom of surface mounted gauges and on the back of flush mounted gauges. Connections shall be externally threaded 1/2 inch NPT with wrench flats.

Dials
Dials shall be 4 1/2 inch nominal diameter and shall be graduated in accordance with the manufacturer’s standard for the specified range. The dials shall be made from corrosion resistant material.
Dial markings shall be black upon a non-glaring white finish.
Element and Gauge Movement
The element should be a single bourdon tube. For ranges less than 15 psig, bellows may be used. The gauge movement mounting shall be integral with the socket.
The element and socket material, unless otherwise specified by the Owner’s Engineer, shall be AISI 316 stainless steel drawn, welded and drawn, or as welded.
The pressure element shall be capable of withstanding intermittent overranging up to a minimum of 1.3 times full scale pressure without taking a permanent set or requiring recalibration. Elements in vacuum service shall be designed to withstand full vacuum without shifting calibration more than 0.5% of range.
The gauge movement shall be adjustable for calibration and the gauge pointer shall be fitted with a vernier screw to permit precise adjustment of the pointer position without removal of the pointer from the shaft.
The gauge movement shall be the manufacturer’s standard design and shall be all stainless steel or stainless steel in combination with other compatible corrosion resistant materials.
Gauge accuracy shall be 0.5% of the entire range of the gauge.

DIAPHRAGM SEAL DEVICES

When specified, diaphragm seal devices for isolating the actuating element from the process fluid shall be provided. The diaphragm seal device shall be supplied completely assembled with the pressure gauge and seal fluid.
Diaphragms shall be stainless steel unless otherwise specified. Bottom housing material shall be carbon steel unless otherwise specified.
An inert liquid shall fill the entire system between the diaphragm of the seal device and the elastic element. Unless otherwise specified, the filling liquid shall be silicone.

6.0 LIQUID FILLED CASES

When specified, gauges with liquid-filled cases shall be supplied for vibrating services and highly corrosive atmospheres. Unless otherwise specified, the fill liquid shall be silicone.

PNEUMATIC INDICATING RECEIVER GAUGES

Pneumatic indicating receiver gauges shall conform to the requirements of ASME B40.1 Class 2A.
Pressure connections for receiver gauges shall be externally threaded 1/4 inch NPT with wrench flats.
Elements shall be bronze, unless otherwise specified, and designed for a 3 to 15 psig pressure range. Dials shall be graduated for the range specified on the Instrument Data Sheet.
Dial size shall be 6 inch nominal diameter.

GENERAL SERVICE GAUGES

General services gauges shall conform to the requirements of ASME B40.1, Class 1A unless otherwise specified and approved by the Owners engineer.
Pipe threads shall be tapered and shall conform to ASME B1.20.1.
Design and materials not specified shall be in accordance with the manufacturer’s standards suitable for the operating and design conditions specified on the Pressure Gauge Data Sheet EP 12-1-19DS.
All pressure gauges shall have safety type cases consisting with a solid front and a blowout back or disc. Gauge lens shall be shatterproof.
Dials shall be 2 1/2 inch or 3 1/2 inch nominal diameter as specified on the data sheet. Dials shall be graduated in accordance with the Manufacturer’s standard for the specified range. The dials shall be made from corrosion resistant material. Dial markings shall be black upon a non- glaring white finish.
The gauge movement shall be the Manufacturer’s standard design and shall be all stainless steel or stainless steel in combination with other compatible corrosion resistant materials. Gauge accuracy shall be 0.1% of the full range of the gauge.

INSTRUMENT GAUGES

Pressure gauges for indication of supply, output, and signal pressure on pneumatic instruments shall conform to the requirements of ASME B40.1, Class B unless otherwise specified and approved by the owners engineer.
Pipe threads shall be tapered and shall conform to ASME B1.20.1.
Dials shall be no larger than 2 1/2 inch nominal diameter. Larger instrument gauges shall meet the requirement of receiver gauges.

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