Definition of technical terms

PN

Nominal pressure

PMA

Maximum allowable pressure (bar)

PMO

Maximum operating pressure (bar)

PO

Operating pressure (bar)

POB

Operating backpressure

PMOB Maximum operating backpressure (bar)

DPMX Maximum differential pressure (bar)

DPMN Minimum differential pressure (bar)

TMA

Maximum allowable temperature (°C)

TMO

Maximum operating temperature (°C)

TO

Operating temperature (°C)

Designed for a maximum cold hydraulic test

pressure of __ bar g

Permissible working pressure which is dependant on materials, design and

working temperatures/pressures.

That the shell of the product can withstand at a given temperature.

Which is given by the manufacturer.

Sometimes restricted by the pressure limitations of internal mechanisms.

Measured at the product inlet.

Measured at the outlet of the product.

Maximum permissible pressure at the trap outlet allowing correct operation.

Maximum difference between operating pressure and operating backpressure.

Minimum difference between operating pressure and operating backpressure.

Maximum temperature to which the shell of the product can be raised

permanently, at a given pressure.

Maximum temperature for which the operation of the product is guaranteed.

Temperature measured at the inlet of the product being tested.

This is a cold hydraulic test applied to the body only, with no internals fitted.

Note: If, when the internals are fitted, the test pressure should be less, this figure

should be clarified to the end user (see Typical pressure/temperature limits diagram

below)

General information

Product limitations

A standard layout for the Pressure / temperature limits

information is shown opposite.

Pressure / temperature limits

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A

D

B

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its operating range as damage to the internals may occur.

A-B-C Flanged PN25.

A-D-E Flanged ANSI 150.

Note: For hygienic / sanitary clamp ends the maximum

pressure / temperature may be restricted by the gasket or

sanitary clamp used. Please consult Spirax Sarco.

Steam

saturation

curve

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Pressure bar g

The product must not be used in this region.

The product should not be used in this region or beyond

Body design conditions

PMA Maximum allowable pressure

TMA Maximum allowable temperature

Minimum allowable temperature

PMO

Maximum operating pressure PN25

for saturated steam service ANSI 150

PN25

25 bar g @ 50 °C

300 °C @ 17 bar g

-196 °C

19 bar g

13.5 bar g

TMO Maximum operating temperature

222 °C @ 19 bar g

Minimum operating temperature

-10 °C

Note: For lower operating temperatures consult Spirax Sarco.

XYZ14-14.5

DPMX

Maximum differential

XYZ14-10

4.5 bar

10 bar

14 bar

pressure

XYZ14-14

Designed for a maximum cold hydraulic test pressure of 37.5 bar g

Note: With internals fitted, test pressure must not exceed 25 bar g

TI-GCM-02 CM Issue 7

Page 3 of 3

Pressure / Temperature Limits

E

C

For further

'Pressure / temperature limits' diagram and table layouts,

see TI-S24-41, pages 4 and 5.

11.4.4

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