Ingeniero

CONTROLS
&
INSTRUMENTATION
Product
Manual
Boiler Controls • Flowmeters • Control Valves

®

Controls
&
Instrumentation
Product Manual
8th Edition

Copyright © 2004 by Spirax Sarco, Inc.
Spirax Sarco Product Manual
Eighth Edition

All rights reserved.
No part of this publication covered by the copyrights hereon may be reproduced or copied in any form
or by any means graphic,electronic, or mechanical without written permission of Spirax Sarco, Inc.

Printed in the United States of America 12/03

Spirax Sarco has a broad range of products tailored to meet the vast needs of
steam and process fluid users everywhere. For years, Spirax Sarco has fulfilled
these needs and today strives to improve this technology as we are in the 21st
Century.
Steam technologycontributes to our way of life in the manufacturing of just about
everything we eat, drink, wear or use whether in our homes or the facilities in
which we work. Steam is the prime carrier of heat in process industry, as well as
an efficient means of space heating, and it is also gaining importance as a
sterilizing medium. Spirax Sarco is committed to the development and use of
steam and for over90 years the company’s vast knowledge of steam
applications in conjunction with its wide product range has become an integral
part in energy conservation in industry as well as commercial applications
throughout the world.
Today, the Spirax Sarco companies employ more than 3,700 people around the
world giving total customer support through 105 Spirax Sarco sales offices and
offices in 37countries – all of these in close contact with engineers and
designers of plants.
This close knit relationship assures customer satisfaction everywhere and
in- turn ensures the adaptability of the Spirax Sarco factories in the United
States, North and South America, Europe, the Far East and Africa to the
ever-changing world around us.
Spirax Sarco is committed to quality and excellence now andinto the future.

The best choice for reliable equipment to fulfill the needs of steam
and process fluid users with the right price, at the right place and time.

To contact your local Spirax Sarco Representative, call:

Toll Free 1-800-883-4411

iii

How To Use This Book

Accepted international designations for limiting conditions are used throughout this catalog.
An explanation ofPressure Shell Design Conditions and Limiting Operating Conditions follows:

Pressure Shell Design Conditions:
• PMA - Maximum Allowable Pressure
• TMA - Maximum Allowable Temperature
These are the maximum pressures and temperatures to which the pressure shell (body, cover, bolting, etc.) of the product may be safely and permanently exposed. The product may or may not operate
properly atthese maximum conditions; the internal parts may be damaged or destroyed, but the pressure-retaining components will not break or become permanently
distorted. It is sometimes permissible to exceed the maximum allowable conditions temporarily. For
example, a cold hydraulic test at 1-1/2 times the cold PMA is usually permitted.
Because the maximum allowable pressure depends on the temperature,there is no one value for
PMA. Quoting only the cold PMA without mentioning the corresponding temperature could be misleading.
PMA is usually given at three temperatures:
• Cold
• Maximum Allowable Saturated Steam Temperature
• Maximum Allowable Temperature
There is only one value for maximum allowable temperature (TMA); the corresponding pressure
range is given in this literature.
PMA andTMA are strictly safety related. They have very little to do with the actual operation of the
product.

Limiting Operating Conditions:
• Maximum Operating Pressure - PMO
• Maximum Operating Temperature
PMO is the maximum fluid (steam, gas or liquid) pressure at which the product will operate properly.
Depending on the type of product, PMO may or may not be related to temperature. Unless...