PRESSURE SENSOR

ACCESSORIES2008-CHEM-832008-CHEM-632008-CHEM-27

2008-CHEM-129 2008-CHEM-147

1

2

Introduction

Categories/Kinds of Pressure Sensing Accessories

Purpose

References

SYNOPSIS

3

Definition To avoid excessive maintenance problems

and damage of instruments, special accessories provide a safe and reliable working of instrument as well as the process

Working Principle

INTRODUCTION

4

Valve Manifolds

Bleed (Vent) Fittings

Pressure Pulsation Damping

Fill Fluid Mechanism

Remote and Chemical Seals

CATEGORIES/KINDS OF PRESSURE SENSING ACCESSORIES

5

Three Valve ManifoldValve Manifolds

A fourth valve called a “bleed” valve used to vent trapped fluid pressure to atmosphere

6

Two block valves are left open to allow process fluid pressure to reach the transmitter. The equalizing valve is left tightly shut so no fluid can pass between the “high” and “low” pressure sides

7

Five Valve Manifold

For normal operation and maintenance Never open while both block valves

8

Bleed (Vent) FittingsClose-up views of a bleed fitting both assembled (left) and with the plug fully extracted from the fitting (right)

Bleed fittings installed in two different ways

9

Pressure Pulsation Damping

An oil-filled pressure gauge Snubber

10

Electrical Pressure Snubber

11

Fill Fluid Mechanism Fill the pressure sensor mechanism with a clean liquid (called a fill fluid) Transfer pressure from the process fluid to the fill fluid

12

Remote and Chemical Seal

13

Pressure gauge with a chemical seal diaphragm

Thin metal isolating diaphragm Chemical Seal Diaphragm

14

Electronic PT Remote Seal

Capillary tube with coiled metal (“armor”) sheath

Close-up view of the sealing diaphragm with corrugated design

15

Water Traps & Pigtal Siphon

Pigtail Siphons Transmitter with Pigtail Siphons

16

Singh S.K., “Industrial Instrumentation and Control”, Tata McGraw Hill Publishing Company Limited New Delhi, Edition Ist, Chapter 12, Page 393-397

Tony R. Kuphaldt, Jan11, 2009, lessons in industrial instrumentation, Creative Commons, page 397-425

http://iamechatronics.com/notes/general-engineering

Dr. Shahid Naveed, Dr. Ing Naveed Ramzan & Ms. Sana Yousuf 2011, Industrial instrumentation, First Edition, Allied Book company, Pages 77-78

REFERENCES