Product Overview

Spirax Sarco Single and Double Window Sight Glasses are threaded connection sight devices, available in brass and bronze body materials depending on size, suitable for industrial applications requiring visual observation of media conditions. Products comply with European Pressure Equipment Directive 97/23/EC, EN 10204 2.2 certificate available upon request (must be specified when ordering), ensuring product quality and compliance.

Technical Specifications

Pressure/Temperature Limits

Parameter	Value
Body Design Conditions	PN5
Max. Allowable Pressure (PMA)	5 bar g @ 90°C
Max. Allowable Temperature (TMA)	148°C @ 3.5 bar g
Min. Allowable Temperature	-29°C
Max. Working Pressure on Saturated Steam (PMO)	3.5 bar g
Max. Working Temperature (TMO)	148°C
Min. Working Temperature	0°C
Design Max. Cold Hydraulic Test Pressure	7 bar g
Max. Test Pressure (Steam, PTMX)	3.5 bar g

Note

Minimum working temperature is 0°C, consult Spirax Sarco below this temperature.

Sizes and Pipe Connections

• Single Window Sight Glass: Sizes 3/8", ½", ¾", 1", BSP or NPT threaded connection
• Double Window Sight Glass: Sizes ½", ¾", 1", 1¼", 1½", 2", BSP or NPT threaded connection

Materials of Construction

No.	Part	Size Range	Material	Standard
1	Body	½" - 1"	Brass	EN 12165 CW617N
1	Body	1¼" - 2"	Bronze	BS EN CC491K
2	Window Frame	All sizes	Brass	EN 12165 CW617N
3	Window	All sizes	Toughened Soda Lime Glass	BS 3463
4	Top Gasket	All sizes	Reinforced Graphite Sheet	-
5	Bottom Gasket	All sizes	Reinforced Graphite Sheet	-

Dimensions and Weights

Single Window Sight Glass

Size	A	B	C	D	E	F	Weight
3/8"	89	16	32	64	50	4.8	0.6 kg
½"	89	16	32	64	50	4.8	0.6 kg
¾"	89	19	35	64	50	4.8	0.7 kg
1"	87.5	24	38	64	50	4.8	0.9 kg

Double Window Sight Glass

Size	A	C	D	E	F	Weight
½"	89	32	64	50	4.8	0.9 kg
¾"	89	32	64	50	4.8	0.9 kg
1"	89	35	64	50	4.8	1.2 kg
1¼"	108	51	73	50	4.8	1.9 kg
1½"	108	51	73	50	4.8	1.8 kg
2"	114	57	76	50	4.8	2.5 kg

Note

Dimensions in mm, weights are approximate values.

Safety Information

Warning

1. Condensate in certain applications may dissolve the window glass, especially when water contains corrosive alkaline or acidic substances, regular inspection of window glass condition is required
2. If window glass thinning is observed, replace immediately to prevent glass breakage
3. Safety glasses must be worn to protect eyes when observing media through the window
4. Protective measures should be taken to ensure broken glass does not cause injury to personnel and equipment in case of sight glass failure

Installation Instructions

1. Isolation valves should be installed before and after the sight glass, upstream isolation valve should be closed first to prevent pressure overload
2. When installed after blast discharge traps (such as thermodynamic traps), maintain at least 1 meter distance to avoid thermal and pressure shock to sight glass window
3. Adequate maintenance space must be provided during installation for subsequent maintenance operations
4. For detailed installation procedures, refer to the Installation and Maintenance Instructions (IM-S32-04) provided with the product

Recommended Tightening Torque

No.	Part	Tightening Torque (N·m)
2	Window Frame	60 - 65

Spare Parts

Single Window Sight Glass Spare Parts

Double Window Sight Glass Spare Parts

Available Spare Parts

Spare Part Name	Part No.
Window and Gaskets	3, 4, 5
Gasket Set	4, 5

Spare Parts Ordering Instructions

1. When ordering spare parts, use the spare part names listed above and clearly specify the sight glass model and size
2. Spare parts ordering example: 1-Window and Gaskets for 1" Double Window Sight Glass

Ordering Information

1. When ordering, clearly specify product model, size, threaded connection type, body material and other key information
2. If EN 10204 2.2 certificate is required, it must be specified when ordering
3. Product ordering example: 1-Spirax Sarco 1" Double Window Sight Glass, BSP threaded connection, brass body with removable toughened soda lime glass

Disposal

This product can be recycled. Proper disposal will not cause adverse environmental impact. Disposal should comply with local environmental regulations.