Data Sheet 810317-07

Issue Date: 03/18

Steam Trap
MK 45-1, MK 45-2, MK 45A-1, MK 45A-2
PN 40 / Class 300
DN 15, 20, 25 (½", ¾", 1)

Description
Thermostatic steam trap with corrosion-resistant thermostatic capsule. With Y-type strainer and integrated non-return action.
Do not expose the control membrane capsule to superheat conditions above 5°C.
Steam traps with standard capsule "N" discharge condensate with approx. 10 K below boiling temperature, traps with capsule
"U" with an undercooling of approx. 30 K and traps with capsule "H" with approx. 5 K undercooling.
MK 45-1, MK 45A-1 with tandem seat (double sealing)
Particularly for low condensate flowrates. Optionally with standard capsule 5N1 or special capsule 5U1 or 5H1.
MK 45 with flanges MK 45-2, MK 45A-2 with single seat
For larger condensate flowrates. Optionally with standard capsule 5N2 or special capsule 5U2 or 5H2.

Pressure /Temperature Ratings & End Connections

MK 45, flanged PN 40, EN 1092-1
Pressure1) p [barg] 40.0 37.1 33.3 30.4 27.6 25.7 23.8 13.1
Temperature1) T [°C] -10/20 100 200 250 300 350 400 450
Max. admissible differential pressure ∆PMX [bar] / [psi] 32 / 465
Admissible service temperature Saturated steam temperature
Pressure ) p
1 [psig] 580 537.95 483 441 400 373 345 190
Temperature1) T [°F] 14/68 212 392 482 572 662 752 842
1) Resistance limits for body/cover to EN 1092-1

MK 45, flanged Class 150, ASME B16.5

Pressure1) p [barg] 19.6 17.7 13.8 12.1 10.2 8.4 6.5 5.5
Temperature1) T [°C] -29/38 100 200 250 300 350 400 425
Max. admissible differential pressure ∆PMX [bar] / [psi] 19.6 / 284
Admissible service temperature Saturated steam temperature
Pressure1) p [psig] 284 256.65 200 175 148 122 94 80
Temperature1) T [°F] -20/100 212 392 482 572 662 752 797
1) Resistance limits for body/cover to ASME B 16.5

MK 45, flanged Class 300, ASME B16.5, butt-weld ends EN 12627

socket-weld ends EN 12760, socket-weld ends Class 3000, ASME B16.11
screwed sockets BSP, ISO 228-1, screwed sockets NPT, ASME B16.11
Pressure1) p [barg] 51.1 46.6 43.8 41.9 39.8 37.6 34.7 28.8
Temperature1) T [°C] -10/38 100 200 250 300 350 400 425
Max. admissible differential pressure ∆PMX [bar] / [psi] 32 / 465
Admissible service temperature Saturated steam temperature
Pressure1) p [psig] 741 675.7 635 608 577 545 503 418
Temperature1) T [°F] -20/100 212 392 482 572 662 752 797
1) Resistance limits for body/cover to ASME B 16.5

MK 45A, flanged PN 40, EN 1092-1

Pressure1) p [barg] 40 37.2 31.8 29.9 27.6 26.4 25.7 –
Temperature1) T [°C] -10/20 100 200 250 300 350 400 –
Max. admissible differential pressure ∆PMX [bar] / [psi] 32 / 465
Admissible service temperature Saturated steam temperature
Pressure1) p [psig] 580 539.4 461 434 400 383 373 –
Temperature1) T [°F] 14/68 212 392 482 572 662 752 –
1) Resistance limits for body/cover to EN 1092-1

If the operating temperatures exceed 300°C intercrystalline corrosion may occur. Do not subject the equipment to operating temperatures higher than 300° C unless
intercrystalline corrosion can be ruled out.

MK 45A, flanged Class 150, ASME B16.5

Pressure1) p [barg] 15.9 13.3 11.2 10.5 10 8.4 6.5 –
Temperature1) T [°C] -29/38 100 200 250 300 350 400 –
Max. admissible differential pressure ∆PMX [bar] / [psi] 15.9 / 284
Admissible service temperature Saturated steam temperature
Pressure1) p [psig] 231 200.1 162 152 145 122 94 –
Temperature1) T [°F] -20/100 212 392 482 572 662 752 –
1) Resistance limits for body/cover to ASME B 16.5
End Connections If the operating temperatures exceed 300°C intercrystalline corrosion may occur. Do not subject the equipment to operating temperatures higher than 300° C unless
■ Flange EN 1092-1 B1 PN 40 intercrystalline corrosion can be ruled out.

■ Flange ASME B 16.5 Class 150 RF, 300 RF MK 45A, flanged Class 300, ASME B16.5, butt-weld ends EN 12627
■ Screwed sockets G: ISO 228-1 socket-weld ends EN 12760, socket-weld ends Class 3000, ASME B16.11
screwed sockets BSP, ISO 228-1, screwed sockets NPT, ASME B16.11
■ Screwed sockets NPT: ASME B 16.11
Pressure1) p [barg] 41.4 34.8 29.2 27.5 26.1 25.1 24.3 –
■ Socket-weld ends DIN EN 12760 Temperature1) T [°C] -10/38 100 200 250 300 350 400 –
■ Socket-weld ends ASME B 16.11 Class 3000 Max. admissible differential pressure ∆PMX [bar] / [psi] 32 / 465
■ Butt-weld ends via transition pieces to EN 12627 Admissible service temperature Saturated steam temperature
welded joint geometry ISO 9692-1 Pressure1) p [psig] 600 504.6 423 399 378 364 352 –
code number 1.3 (30° chamfer) Temperature1) T [°F] -20/100 212 392 482 572 662 752 –
1) Resistance limits for body/cover to ASME B 16.5
■ Butt-weld ends via transition pieces ASME B 16.25 If the operating temperatures exceed 300°C intercrystalline corrosion may occur. Do not subject the equipment to operating temperatures higher than 300° C
ASME B 36.10 unless intercrystalline corrosion can be ruled out.
Materials of construction Component Parts MK 45, MK 45A
Type MK 45
Designation EN ASME 1
Body and cover 1.0460 A105
Hexagon-head cap screws 1.7225 A193 B7
2
Gasket Graphite/CrNi
Membrane regulator capsule Hastelloy® 3
Other internals High grade steels
4
Type MK 45A 5
Designation EN ASME
Body and cover 1.4404 A 182 F316L
Hexagon-head cap screws A2-70 A193 B8 6
Gasket Graphite/CrNi
Membrane regulator capsule Hastelloy® 7
Other internals High grade steels 8
9

0
a

Key
1 Hexagon-head screw M 10 x 25
2 Name plate
3 Cover
4 Spring
5 Regulating membrane (capsule)
6 Nozzle insert with non-return cone
7 Bushing (interference fitted, no spare part)
8 Gasket 40 x 48 x 2
9 Body
0 Strainer
a Gasket A 24 x 29
b Sealing plug

Spare parts list see page 3

 Dimensions Weights and dimensions for traps with flanged ends
Flanged EN 1092-1 ASME B 16.5 ASME B 16.5
Type to
L PN 40 Class 150 Class 300
Withdrawal 96 15 20 25 15 20 25 15 20 25
distance DN
1/ 3/ 1" 1/ 3/ 1" 1/ 3/ 1"
2 4 2 4 2 4
Tandem seat
30 D [mm] 95 105 115 88.9 98.4 107.9 95.2 117.5 123.8
MK 45, MK 45A
L [mm] 150 150 160 150 150 160 150 150 160
[kg] 3.7 4.3 4.8 3.7 4.3 4.8 3.7 4.3 4.8
62

Weights and dimensions for traps with butt-weld ends

Butt-weld ends EN 12627 ASME B 16.25
D Type to Edge form to ISO 9692, code number 1.3 ASME B 36.10
15 20 25 15 20 25
DN
1/ 3/ 1" 1/ 3/ 1"
70

2 4 2 4

MK 45, MK 45A for pipe 21.3 x 2.0 26.9 x 2.3 33.7 x 2.6 21.3 x 2.8 26.7 x 2.9 33.4 x 3.4
L [mm] 200 200 200 200 200 200

Withdrawal distance 30 [kg] 2.5 2.5 2.5 2.5 2.5 2.5

Butt-weld ends for other pipe sizes available on request.

Weights and dimensions for traps with socket-weld ends

Withdrawal
distance

Socket-weld
Type ends to DIN EN 12760, ASME B 16.11 Class 3000
30
15 20 25
DN
1/ 3/ 1"
2 4
MK 45, MK 45A
L [mm] 95 95 95
62

[kg] 2.2 2.1 2.0

Weights and dimensions for traps with screwed sockets

Screwed sock-
Type ets to G: ISO 228-1, NPT: ASME B 16.11

15 20 25
70

DN
1/ 3/ 1"
2 4
MK 45, MK 45A
L [mm] 95 95 95
[kg] 2.2 2.1 2.0
Withdrawal distance 30

Stock code #
Spare Parts
Item Designation MK 45-1 MK 45-2
MK 45A-1 MK 45A-2
6 5
Membrane regulator, complete, 5N1 375 109

8 5 6 8 Membrane regulator, complete, 5U1 375 111

Membrane regulator, complete, 5H1 378 521
Membrane regulator, complete, 5N2 375 110
5 6 8 Membrane regulator, complete, 5U2 375 112
Membrane regulator, complete, 5H2 377 589
375 113 375 113
0 ! Strainer set, cpl.
375 382 375 382

0 a
Thermostatic capsule1) 5N1 376165
5 Thermostatic capsule1) 5U1 376166
b Thermostatic capsule1) 5H1 376 173
Thermostatic capsule1) 5N2 376167
5 Thermostatic capsule1) 5U2 376168
Thermostatic capsule1) 5H2 376 174
8 Gasket2) 400 x 48 x 2, graphite 375 159 375 159
! Gasket2) 24 x 29, stainless steel 375 162 375 162
1) Packaged 10 per box. For smaller quantities please contact your local dealer.
2) Packaged 50 per box. For smaller quantities please contact your local dealer.
Steam Trap Capacity Chart for MK 45-1, MK 45A-1
MK 45-1, MK 45-2,
MK 45A-1, MK 45A-2
PN 40 / Class 300
DN 15, 20, 25 (½", ¾", 1)

Capacity Charts 2
The charts show the maximum capacities for hot and cold
condensate. 1
Curve 1
Indicates the max. capacity of hot condensate that steam
traps with 5N.. capsule can discharge with approx. 10 K
below boiling temperature and traps with 5U... capsule can
discharge with approx. 30 K below boiling temperature..
Curve 2
Discharge capacity for cold condensate at 20°C.

Inspection & Certification

Documentation regarding material tests and in-house ex-
amination with test report EN10204 available. All inspection
requirements have to be stated with the enquiry or order. After
supply of the equipment certification cannot be established.
Charges and extent of the above mentioned test certificates
as well as the different tests confirmed therein are listed in
our Price List "Test and Inspection Charges for Standard
Equipment". For other tests and inspections than those listed
Capacity
Flowrate

above, please consult us.

Application of European Directives

Pressure Equipment Directive (PED) Differential pressure
The equipment conforms to this directive and can be used Differential pressure
for the following media:
■ Fluids of group 2 Capacity Chart for MK 45-2, MK 45A-2
ATEX Directive
The equipment does not have its own potential ignition source
and is not subject to this directive.
Static electricity: When installed, static electricity may arise 2
between the equipment and the connected system.
When used in potentially explosive atmospheres, the plant
manufacturer or plant operator is responsible for discharging 1
or preventing possible static charge.
If it is possible for medium to escape, e.g. through actuating
mechanisms or leaks in threaded joints, the plant manufacturer
or plant operator must take this into consideration when
dividing the area into zones.
Capacity
Flowrate

Differential pressure
Supply in accordance with our general terms of business. Differential pressure

GESTRA AG
Münchener Straße 77, 28215 Bremen, Germany
Telefon +49 421 3503-0, Telefax +49 421 3503-393
E-mail info@de.gestra.com, Web www.gestra.de

810317-07/03-18cm (804129-07) · GESTRA AG · Bremen · Printed in Germany