Flowserve MK25-2 User Manual

GESTRA

GESTRA Steam Systems

MK 25/2
MK 25/2S

Installation Instructions 810706-01

Steam Traps
MK 25 . .., DN 40-50



1

Contents

Page

Important Notes

Usage for the intended purpose ......................................................................................8

Safety note ......................................................................................................................8

Danger ............................................................................................................................ 8

Rating pursuant to article 9 of the PED ...........................................................................8

Explanatory Notes

Scope of supply ..............................................................................................................9

Description ......................................................................................................................9

Function .......................................................................................................................... 9

Technical data .........................................................................................................9 – 10

Corrosion resistance .....................................................................................................11

Sizing ............................................................................................................................ 11

Name plate / marking ....................................................................................................11

Installation

MK 25... .........................................................................................................................12

Design with flanges .......................................................................................................12

Design with screwed-sockets ........................................................................................12

Design with socket-weld ends .......................................................................................12

Design with butt-weld ends ...........................................................................................13

Heat treatment of welds ................................................................................................13

Commissioning

MK 25... .........................................................................................................................13

Operation

MK 25... .........................................................................................................................13

Maintenance

Check steam trap ..........................................................................................................14

Clean / exchange capsule and nozzle seat...................................................................14

Clean / exchange strainer .............................................................................................14

Torques .........................................................................................................................15

Spare Parts

Spare parts list ..............................................................................................................15

Annex

Declaration of conformity .............................................................................................. 16

2

Capacity Chart

4

2
3

1

Fig. 1

MK 25/2: Condensate temperature 10 K (degC)

1

below saturation temperature.

2

MK 25/2: Cold condensate at a temperature of

20 °C (start-up capacity).

3

MK 25/2S: Condensate temperature 10 K

(degC) below saturation temperature.

MK 25/2S: Cold condensate at a temperature

4

of 20 °C (start-up capacity).

3

Design MK 25/2

A

B

C

D

R

E

F

G

H

Fig. 2

4

J

I

Design MK 25/2S

A

B

C

D

R

E

F

Fig. 3

G

H

J

I

5

Check Capsule

Thermostatic capsule

Capsule intact

Fig. 4

D for flat seat nozzle support: 5H2

Capsule defective

≥ 4.4 mm

Fig. 5

MLK

≥ 3.8 mm

Fig. 6

6

N

Key

A

Hexagonal bolt

B

Cover

Capsule holder

C

Capsule 5 H 2

D

Nozzle seat

E

Gasket 92.7x 102x1

F

Strainer

G

Body

H

Name plate

I

Hexagon nut

J

Differential pressure rating

K

5 = ∆p 22 bar

R

Regulator

L

Inlet temperature rating

H = ∆t approx. 4 – 5 K

M

Capacity rating

2 = high flowrate

N

Manufacturing code number

7

Important Notes

Usage for the intended purpose

Use multi-capsule steam traps MK 25/2 and MK 25/2 S only for the discharge of
condensed water or for air venting from steam spaces.

Use this equipment only within the specified pressure and temperature ratings and
check corrosion resistance and chemical suitability for the application in question.

Safety note

Installation must only be performed by qualified staff.
Qualified staff are those persons who – through adequate training in engineering, the

use and application of equipment in accordance with regulations concerning steam
systems, and first aid & accident prevention – have achieved a recognised level of
competence appropriate to the installation and commissioning of this device.

Danger

The steam trap is under pressure during operation.
When loosening flanged connections, plugs or the thermostatic capsule,
hot water and/or steam may escape. This presents the risk of severe burns
to the whole body.
Installation and maintenance work should only be carried out when the
system is depressurized: isolate the trap from both upstream and
downstream pressure.

The trap becomes hot during operation.
This presents the danger of severe burns to hands and arms. Installation
and maintenance work should only be carried out when the system is cold.

Sharp edges on internal parts present a danger of cuts to hands. Always
wear industrial gloves for installation and maintenance work.

Rating pursuant to article 9 of the PED1)

Fluid group

Use no yes no yes

Category I

Nominal size DN 40 – 50 40 – 50

CE marking no yes

Type

1

) PED = Pressure Equipment Directive

gas liquid

1212

Exception pursuant

to article 3.3

MK 25/2, CL 150

MK 25/2S, CL 150

MK 25/2, MK 25/2S

PN 40, CL 300

8

Explanatory Notes

Scope of supply

MK 25/2

1 Steam trap MK 25/2
1 Installation manual

MK 25/2S

1 Steam trap MK 25/2 S
1 Installation manual

Description

Thermostatic steam trap with corrosion resistant thermostatic capsule (membrane
regulator). Integral strainer, asbestos-free cover gasket (graphite/CrNi). Installation in
any position.
The thermostatic capsule “H” discharges the condensate with virtually no banking up.

■ MK 25/2 with single seat

With four thermostatic capsules “5H2”. For condensate flowrates up to e. g.
2800 kg/h at ∆p = 5 bar.

■ MK 25/2S with single seat

With nine thermostatic capsules “5H2”. For condensate flowrates up to e. g.
5000 kg/h at ∆p = 5 bar.

Function

The MK 25... is a multi-capsule high-capacity steam trap with four or nine capsules. The
capsule is filled with a liquid which boils at a temperature a few degrees lower than
water. As long as condensate flows through the steam trap the liquid in the capsule is
completely condensed due to the low ambient temperature. The pressure inside the
capsule is lower than the surrounding pressure (service pressure) and the membrane
with the valve disc is pushed in the opening direction. As the condensate temperature
approaches steam temperature, the liquid filling of the capsule starts to boil and
evaporate. The pressure in the capsule rises and the membrane with the valve disc is
moved in the closing direction.

Automatic air-venting is provided both, during start-up and during normal operation.
The correct functioning of the MK 25 is neither affected by fluctuations in the upstream
pressure nor by back pressure.The MK 25 can also be used for thermal air venting.

Technical data

Pressure/Temperature Ratings PN 40

Body material 1.0460 (P250GH / C22.8) / ASTM A105
Nominal sizes (DN) 40, 50
Connection Flanged DIN PN 40
Max. allowable pressure PMA [barg] 40 35 28 21 14.5

[psig] 580 508 406 305 210

Inlet temperature TMA [°C] 20 200 300 400 450

[°F] 68 392 572 752 842

9

Explanatory Notes – continued –

Technical data – continued –

Pressure/Temperature Ratings Class 300

Body material 1.0460 (P250GH / C22.8) / ASTM A105
Nominal sizes (DN) 40, 50
Connection Flanged ASME Class 300
Max. allowable pressure PMA [barg] 51 43.9 38.9 34.6 20.2

Inlet temperature TMA [°C] 20 200 300 400 450

Pressure/Temperature Ratings Class 150

Body material 1.0460 (P250GH / C22.8) / ASTM A105
Nominal sizes (DN) 40, 50
Connection Flanged ASME Class 150
Max. allowable pressure PMA [barg] 19.7 14 10.2 6.5 4.6

Inlet temperature TMA [°C] 20 200 300 400 450

Max. admissible differential pressure1)

Differential pressure ∆PMX [barg] 22

(inlet pressure minus outlet pressure) [psig] 319

1

) Observe pressure/temperature ratings!

[psig] 740 637 565 501 294

[°F] 68 392 572 752 842

[psig] 287 203 149 94.3 66.7

[°F] 68 392 572 752 842

Materials EN DIN ASTM equivalent

Body P250GH (1.0460) C22.8 (1.0460) A105
Cover MK 25/2 P250GH (1.0460) C22.8 (1.0460) A105
Cover MK 25/ 2 S GP240GH (1.0619) GS-C25 (1.0619) A216 WCB
Bolts 42CrMo4 (1.7225) A193 B7
Body gasket Graphite
Thermostatic capsule Hastelloy® / Stainless steel
Other internals Stainless steel

10

Explanatory Notes – continued –

Corrosion Resistance

If the steam trap is used for the intended purpose, its safety is not impaired by
corrosion.

Sizing

The trap body must not be subjected to pulsating loads. The dimensional allowances
for corrosion reflect the latest state of technology.

Name Plate / Marking

Marking acc. to
EN ISO 26552

Nominal size

For further specifications to EN 19 see trap body.

Fig. 7

Capacity rating

Capacity 2800 kg/h

Capacity 5000 kg/h

S

11

Installation

MK 25...

The steam trap MK 25... can be installed in any position. In the case of a horizontal
installation, make sure that the cover is at the top.

Flanged Traps

1. Take care of correct position of installation.

2. Observe direction of flow. The flow arrow is on the trap body.

3. Consider space required for opening trap. When the trap is installed a minimum

space of 70 mm (MK 25/2) or 100 mm (MK 25/2 S) is required for removing
cover B.

4. Remove plastic plugs. They are only used as transit protection.

5. Clean seating surfaces of both flanges.

6. Install steam trap.

Screwed-Socket Traps

1. Take care of correct position of installation.

2. Observe direction of flow. The flow arrow is on the trap body.

3. Consider space required for opening trap. When the trap is installed a minimum

space of 70 mm (MK 25/2) or 100 mm (MK 25/2 S) is required for removing
cover B.

4. Remove plastic plugs. They are only used as transit protection.

5. Clean internal threads of screwed sockets.

6. Install steam trap.

Socket-Weld Traps

1. Take care of correct position of installation.

2. Observe direction of flow. The flow arrow is on the trap body.

3. Consider space required for opening trap. When the trap is installed a minimum

space of 70 mm (MK 25/2) or 100 mm (MK 25/2 S) is required for removing
cover B.

4. Remove plastic plugs. They are only used as transit protection.

5. Clean thermostatic capsule as described under Maintenance.

6. Clean socket-weld ends.

7. To install trap only apply arc welding processes 111 and 141 in accordance with
DIN EN 24063.

12

Installation – continued –

Butt-Weld Traps

1. Take care of correct position of installation.

2. Observe direction of flow. The flow arrow is on the trap body.

3. Consider space required for opening trap. When the trap is installed a minimum

space of 70 mm (MK 25/2) or 100 mm (MK 25/2 S) is required for removing
cover B.

4. Remove plastic plugs. They are only used as transit protection.

5. Clean butt-weld ends.

6. To install trap only apply arc welding processes 111 and 141 to DIN EN 24063 or
gas welding process 3 to DIN EN 24063.

Attention

■

Only qualified welders certified e. g. according to DIN EN 287 may weld
the steam trap into pressurized lines.

■

Do not insulate steam trap.

Heat treatment of welds

A subsequent heat treatment of the welds is not required.

Commissioning

MK 25...

Make sure that the flanged connections of the MK 25 are permanently bolted and tight.

Operation

MK 25...

Please note that maintenance is required for certain operation modes (see
Maintenance).

13

Maintenance

GESTRA steam traps MK 25... do not require any special maintenance. However, if
used in new installations which have not been rinsed it may be necessary to check
and clean the regulator (nozzle seat, capsule and capsule holder) and the strainer.

Check steam trap

You can check steam traps MK 25... for steam loss during operation by using the
ultrasonic measuring unit VAPOPHONE

®

or the test unit TRAP

test

®

.

Should you detect any loss of live steam clean the trap and/or replace regulator.

Clean/exchange capsule and nozzle seat

1. Take heed of the note “Danger” on page 8.

2. Undo hexagon-head bolts A and remove cover B from trap body H.

3. Remove capsule holder C.

4. Remove capsule D and clean it. Unscrew nozzle seat E.

5. Remove old gasket F and strainer G.

6. Replace capsule D in case of visible signs of wear or damage.

7. Clean body, internals and all gasket surfaces.

8. Apply heat-resistant lubricant to all threads and seating surfaces of the nozzle seat
and the cover (use for instance WINIX

®

2150).

9. Install strainer G, screw in nozzle seat E and tighten with a torque of 140 Nm.

10. Position capsule D onto the nozzle seat E and press evenly, such that the capsule
snaps into place.

11. Insert new gasket F.

12. Put cover B onto the body H. Tighten hexagon-head bolts A alternately and in
several steps to a torque of 45 Nm.

Tools

■

Spanner A. F.18 mm to DIN 3113, form B

■

Spanner A. F. 36 mm to DIN 3113, form B

■

Torque spanner 20 – 140 Nm to DIN ISO 6789

Clean/exchange strainer

1. Take heed of note “Danger” on page 8.

2. Undo hexagon-head bolts A and remove cover B from trap body H.

3. Completely unscrew regulator R.

4. Remove strainer G.

5. Remove old gasket F.

6. Clean body, internals and all gasket surfaces.

7. Apply heat-resistant lubricant to all threads and the seating surfaces of the nozzle
seat and the cover (use for instance WINIX

®

2150).

8. Insert new gasket F.

9. Install strainer G.

10. Screw in regulator R and tighten with a torque of 140 Nm.

11. Put cover B onto the body H. Tighten hexagon-head bolts A alternately and in
several steps to a torque of 45 Nm.

WINIX® 2150 is a registered trademark of WINIX GmbH, Norderstedt

14

Maintenance – continued –

Tools

■

Spanner A. F. 18 mm to DIN 3113, form B

■

Spanner A. F. 36 mm to DIN 3113, form B

■

Torque spanner 20 – 140 Nm to DIN ISO 6789

Torques

Item Designation Torque [Nm]

E

J

A

All torques are based at 20°C room temperature. Do no apply lubricant to threads.

Nozzle seat MK 25/2 / MK 25/2 S 140

Cover bolts / hexagonal nuts 45

Spare Parts

Spare Parts List

Item

R
D
F
G

1

) Packed 10 per box. Contact your local dealer for smaller quantities.

2

) Packed 20 per box. Contact your local dealer for smaller quantities.

Designation

Regulator with body gasket 098770 098774

Capsule 5H21) 376174 376174

Gasket2) 92.7x102 x 1 375699 375699

Strainer, body gasket 375698 375698

Stock code

MK 25/2 MK 25/2 S

15

Annex

Declaration of Conformity

We hereby declare that the pressure equipment MK 25/2 and MK 25/2 S, nominal
sizes DN 40 - 50, conform to the following European Directive:

■

EC Pressure Equipment Directive (PED) No. 97/23 of 29 May 1997

These steam traps are pressure equipment as defined in article 1, section 2.1.4 of the
PED.

Applied conformity assessment procedure as described in Annex III: Module A
This declaration is no longer valid if modifications are made to the equipment without

consultation with us.

Head of the Design Dept.

Uwe Bledschun

Academically qualified engineer

Bremen, 5

GESTRA AG

th

December 2001

Quality Assurance Representative

Lars Bohl

Academically qualified engineer

16

171819

www.gestra.de

GESTRA

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GESTRA ESPAÑOLA S.A.

Luis Cabrera, 86-88
E-28002 Madrid
Tel. [phone]
Fax 00 3491 / 41 36 747; 51 52 036
E-mail: [e-mail]

Great Britain

Flowserve Flow Control (UK) Ltd.

Burrel Road, Haywards Heath
West Sussex RH 16 1TL
Tel. [phone] / 31 44 00
Fax [phone] / 31 45 57
E-mail: [e-mail]

Italia

Flowserve S.p.A.

Flow Control Division
Via Prealpi, 30
l-20032 Cormano (MI)
Tel. [phone]
Fax [phone]
E-mail: [e-mail]

Polska

GESTRA POLONIA Spolka z.o.o.

Ul. Schuberta 104
PL - 80-172 Gdansk
Tel. [phone] od 10
Fax [phone]
E-mail: [e-mail]

Portugal

Flowserve Portuguesa, Lda.

Av. Dr. Antunes Guimarães, 1159
Porto 4100-082
Tel. [phone]
Fax [phone]
E-mail: [e-mail]

USA

Flowserve DALCO Steam Products

2601 Grassland Drive
Louisville, KY 40299
Tel.: 00 15 02 / 4 95 01 54, 4 95 17 88
Fax: 00 15 02 / 4 95 16 08
E-Mail: [e-mail]

GESTRA AG

Postfach 10 54 60, D-28054 Bremen
Münchener Str. 77, D-28215 Bremen
Telefon [phone]
Telefax [phone]
E-Mail [e-mail]
Internet www.gestra.de

810706-01/1104c · © 2001 GESTRA AG · Bremen · Printed in Germany

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