Spirax Sarco steam injectors IN15, IN25M and IN40M use steam to heat water or other fluids. During operation, the steam jet draws liquid through annular openings, mixes with it, and discharges the heated water into the tank. Circulation generated by the injector ensures thorough mixing and prevents temperature stratification. Three injector sizes cover a wide range of applications. The smallest model, IN15, has internal and external threads and can be installed directly through the tank wall or connected to the tank by piping. IN25M and IN40M are available with external threads and socket-weld ends and are installed in the same way as IN15. When higher flow rates are required, two or more injectors can be installed in parallel.

Key Features

• Fully stainless steel construction

• Ideal for boiler feedwater heating and deaeration

• Efficient steam heating of water and other fluids

• Heating, mixing and circulation

• No moving parts

• Compact design

• Minimal noise and vibration

Pressure and Temperature Limits

Body design rating	PN25
Minimum operating pressure	0.5 bar g
Maximum saturated steam condition	17 bar g @ 207 °C
Maximum heating temperature (open tank)	90 °C

Materials

Austenitic stainless steel ASTM A351 CF3M

Weight (Approximate)

Model	Weight
IN15	0.4 kg
IN25M	0.8 kg
IN40M	1.6 kg

Ordering Information

Example: 1- Spirax Sarco IN25M steam injector, 1” BSPT threaded connection, austenitic stainless steel ASTM A351 CF3M.

Available Models

IN15, ½” female thread and 1” male thread, BSPT or NPT.

Other injector options are shown below:

	IN25M	IN40M
BSPT male thread	1”	1½”
NPT male thread	1”	1½”
Socket weld	1” Schedule 80	1½” Schedule 80

Safety Information, Installation and Maintenance

Detailed installation and maintenance instructions are supplied with the product. The information below does not contain sufficient installation safety information. For safety information, see IM-GCM-10.

Flow Rate — Selecting a Steam Injector

Steam injectors are selected according to steam flow rate. The data in the table below is based on an open tank with a depth of 3m. Control valve selection also affects steam flow rate. Higher flow rates can be achieved by arranging two or more injectors horizontally.

Installation Considerations

Install the injector at a low position in the tank, preferably on the centerline, with the steam jet directed horizontally. Piping may be installed inside or outside the tank. Steam piping must be properly supported to prevent vibration and stress on the tank wall. Use of a suitable adhesive on threaded connections is recommended.

The pipe size should be the same as the injector size; for example, an IN25M injector should use 25mm piping. For multiple injectors, pipe sizes should be as follows:

Number of injectors	Model	Minimum pipe diameter
2	IN15	20 mm
2	IN40M	65 mm
3	IN40M	80 mm

Maintain a minimum distance of 150mm between two injectors or between an injector and the tank wall. The injector outlet should be positioned as far as possible from the tank wall. See the installation and maintenance instructions for further details.

System Example

The table below shows steam flow rates for combinations of injectors, valves and controllers used with an open tank. Values not shown in the table can be calculated by linear interpolation. For specific applications, contact Spirax Sarco engineers.

The table is for example only; valve and controller combinations may not be suitable in some markets. Note: Steam pressure is greatly reduced inside the injector. Therefore, an undersized control valve, or an injector that is too large, can result in poor injection and mixing.

Model	IN15	IN25M	IN40M
System pressure bar g	Saturated steam flow kg/h
0.5	11	75	222
1	20	135	400
2	48	175	580
3	66	280	805
4	84	350	970
5	102	410	1125
6	120	500	1295
7	138	580	1445
8	156	640	1620
9	174	700	1820
10	192	765	1950
11	210	830	2250
12	228	900	2370
13	246	975	2595
14	264	1045	2710
15	282	1095	2815
16	300	1170	3065
17	318	1225	3200