Description

Spirax Sarco SG253 sight glass with a ductile iron body, dual windows, and flanged connections.

Available Models

ModelSKU
DN15 SG2531300093
DN20 SG2531301093
DN25 SG2531302093
DN32 SG2531303093
DN40 SG2531304093
DN50 SG2531305093

Standards

This product complies with the European Pressure Equipment Directive 97/23/EC. A stamped marking can be provided on request.

Certificates

A test report can be supplied for this product. A certificate to EN 10204 3.1 can also be provided when specified. Note: If a certificate is required, please state this when ordering.

Sizes and Piping Connections

DN15, DN20, DN25, DN32, DN40 and DN50; flanges to EN 1092 PN25 and BS 1560 (ANSI) Class 150.

Pressure/Temperature Limits

This product has specific pressure/temperature limit zones. A - B corresponds to EN 1092 PN25 flanges, and A - C corresponds to BS 1560 (ANSI) Class 150 flanges. The applicable limits are as follows:

Body design conditionsPN25ANSI 150
PMA - Maximum allowable pressure25bar g@100℃17.2bar g@35℃
TMA - Maximum allowable temperature280℃ @18bar g280℃ @10bar g
Minimum allowable temperature-10℃-10℃
PMO - Maximum operating pressure with saturated steam21bar g13.8bar g
TMO - Maximum operating temperature280℃280℃
Minimum operating temperature (consult Spirax Sarco below this temperature)0℃0℃
Maximum cold hydraulic test pressure38bar g30bar g
PTMX - Maximum test pressure (steam)21bar g13.8bar g

Materials

No.PartMaterial
1BodyDuctile iron DIN 1693 GGG 40.3
2CoverDuctile iron DIN 1693 GGG 40.3
3Sight glassBorosilicate glass DIN 7080
4GasketReinforced exfoliated graphite
5Cover boltsSteel BS 3692 Gr. 8.8

Weight

SizePN25 weight (kg)ANSI 150 weight (kg)
DN153.23.2
DN204.14.1
DN255.05.0
DN325.95.9
DN409.19.1
DN5010.910.9

Safety Information, Installation and Maintenance

For detailed information, refer to the Installation and Maintenance Instructions (IM-S32-04) supplied with the product.

Warning: In some applications, condensate can have a dissolving effect on sight glass, particularly when the water contains corrosive alkaline or acidic substances. Regular inspection of sight glass is therefore recommended. If any thinning is observed, replace the glass immediately. Wear safety glasses to protect your eyes when viewing. Take appropriate measures to ensure that broken glass does not injure personnel or damage equipment if sight glass fails.

Installation and maintenance: Install isolation valves upstream and downstream of sight glass. Close the upstream isolation valve first to prevent pressure overload. Sight glass can be installed horizontally or vertically downstream of a steam trap. When installed downstream of a blast-discharge steam trap, such as a thermodynamic steam trap, maintain a distance of at least 1 meter. This helps protect sight glass from thermal and pressure shock. Ensure sufficient access for inspection and maintenance.

Disposal: This product is recyclable and, when disposed of properly, will not create environmental problems.

Ordering

Example: 1 - Spirax Sarco DN 20 SG253 sight glass, ductile iron body, EN1092 PN25 flanged connection.

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