The spare parts available are shown in solid outline. Parts drawn in
broken line are not supplied as spares.
Available spares
Internals set for MST21
How to order spares
3, 4, 5, 6, 7
Always order spares by using the description given in the column
headed 'Available spares' and state the size, model number and
capsule reference.
Example: 1 off Internals set for a Spirax Sarco 1⁄4" MST21 balanced
pressure thermostatic steam trap having a 'STD' fill capsule for
operation at 10°C below steam saturation temperature.
1
Differential pressure bar (x 100 = kPa)
Cold water capacity
Hot water capacity
Size
A
B
C
D
Weight
1⁄4"
1⁄2"
"
3⁄4"
1"
50.5
8.5
10
61.0
12.5
14
68.0
14.0
14
68.0
14.0
14
75.0
14.0
14
45
0.34
45
0.48
45
0.48
45
0.48
45
0.48
6
4
B
A
3
5
C
D
7
2
For full details see the Installation and Maintenance Instructions
(IM-P125-07) supplied with the product.
Installation note:
The MST21 is designed for installation with the capsule in a vertical
line with the inlet at the top and the outlet at the bottom. This will
ensure it is self-draining. If fitted in a horizontal line the trap should
be proceded by a short drop-leg.
Caution:
The body/cover gasket contains a thin stainless steel support ring,
which may cause physical injury if it is not handled and disposed of
carefully.
Disposal:
This product is recyclable. No ecological hazard is anticipated with
the disposal of this product, providing due care is taken.
Example: 1 off Spirax Sarco 1⁄4" MST21 balanced pressure
thermostatic steam trap having a 'STD' fill capsule for operation
approximately at 10°C below steam saturation temperature. The
connections are to be screwed NPT.
Recommended tightening torques
Item
1 and 2
Size
1⁄4"
1⁄2"
"
3⁄4"
1"
or
mm
N m
100 - 110
100 - 110
100 - 110
100 - 110
100 - 110
22
32
32
36
41
C
o
n
d
e
n
s
a
t
e
k
g
/
h