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Operation Manual

 

 

 

 

11 Replacing Mechanical Seal 

 

 

 
 

 
 

 

 

 

 
 

 
 

11.1 Single mechanical seal

 

 

 

The  seal  comprises  of  a  rotary  face  with 
associated 'O' ring which is located in the rotor 
with two pins providing the drive. A wave spring 
provides a closing force through the static face. 
Two  pins  provide  anti-rotation  fixing  for  one 
static face with associated static 'O' ring. 

 

 

 

ITEM

 

 

DESCRIPTION

 

42 
43 
45 
64 
65 
66 
76 
77 
82 
83 
85 

Shaft Sleeve 
‘O’Ring Sleeve/Rotor 
‘O’Ring Shaft/Sleeve 
Clip Shaft Sleeve Retention 
‘O’Ring Seal Housing/Rotorcase 
Seal Housing 
'O' Ring Mech Seal/Rotor 
'O

’Ring Mech Seal/Housing 

Seal Face Static 
Seal Face Rotary 
Wave Spring 

 
 

11.2 Single mechanical seal removal

 

 

 

1. 

Remove the gland guards (21). 

 

 

Thoroughly clean the inside and outside 
of the seal area on the rotorcase and the 
bores of the rotor. The static element  of 
the seal and the seal housing (66) should 
be removed as an assembly. 

 

3. 

Use a suitably sized screwdriver to lever 
between the seal housing and shaft 
sleeve  (42).  This  will  ease  the  seal 
assembly  out of the rotorcase. 

 

4.      With the static seal assembly on a suitable 

work bench use a screwdriver or lever in 
the wave spring recess to prise the static 
seal  face  (82)  out  of  the  seal  housing. 
The  wave  spring  (85)  can  be  pressed 
over the drive pins and removed. 

 

5.      Use a screwdriver/lever to prise the rotary 

seal (83) face out of the rotor. 

STP125    Page  24

 

Summary of Contents for STP 125

Page 1: ...MIS TP 125 E N1 0701 OPERATION AINTENANCE and INSTALLATION MANUAL and PARTS LIST ROTARY LOBE PUMP STP 125 STP125 VERSION 03 February 3 2015...

Page 2: ......

Page 3: ...on 5 3 2 Principle of operation 5 3 3 Pump dimensions 6 3 4 Pump weight 6 3 5 Pump displacement 6 3 6 Pump information chart 6 3 7 Pressure relief valve 6 4 0 SystemDesignandInstallation 4 1 System de...

Page 4: ...he timing gears 16 8 11 Shaft and bearing removal 16 9 0 Assembly 9 1 Fitting shafts into the bearing housing 17 9 2 Fitting the front seal retainers 17 9 3 Fitting timing gears and setting rotor timi...

Page 5: ...ating tank 12 1 Heatingtankremoval 23 12 2 Heatingtankfitting 23 13 0 Relief valve 13 1 Disassembly reliefvalve 24 13 2 Assembly reliefvalve 24 14 0 Faults causes and remedies 25 15 0 Torque settings...

Page 6: ...he materials of construction and product seals are compatible with the pumping application and that adequate NPSH is available For specific guidelines contact your supplier quoting pump serial number...

Page 7: ...rstart inthe wrongdirection of rotation with liquid in the pump Never put your hands or fingers inside the port connections Operation Always observe the technical data Nevertouchthepumporthepipelines...

Page 8: ...Wash with soap and water Eyes Flushwithwater seekmedical attention In all cases if symptoms persist seek medical attention Material Use Majorhazard SILICONE SEALANT GEARBOX SEAL RETAINERS GENERAL SEA...

Page 9: ...enable the pump to be lifted either with or without the hydraulic drive fitted Alternatively slings should be wrapped around the ports and the hydraulic drive flange Note To stop the slings slipping a...

Page 10: ...otors The direction of flow is reversed by changing the direction of rotation of the pump s drive shaft The pumping principle is as follows The volume at the inlet increases when the rotors rotate and...

Page 11: ...gall 3 6Pumpinformationchart 3 7Pressure relief valve A integral relief valve is available It can be used regardless of the direction of rotation A manual override is also available The relief valve i...

Page 12: ...common dischargelines Do Make the necessary piping arrangements if steam is required for heating cooling tanks Plan View SuctionLine Do not Subject the pump to rapid temperature changes during C I P C...

Page 13: ...Use long radius bends wherever possible Provide Valves on each side of the pump to isolate the pump whennecessary Keep Pipework horizontal where applicable to reduce air locks Include eccentric reduce...

Page 14: ...its effectiveness If this cap is lost at any time it is important that a replacement of the same type is fitted immediately 5 1Lubricatingthepump The gearbox should be filled to the mid point of the s...

Page 15: ...ump connections and pipework joints tight and leak free 4 Is there lubrication in the pump and drive unit 5 Are the pipework valves open 6 Are all safety guards in place 7 Start then stop the pump to...

Page 16: ...te the pump drive from all power and control supplies 3 Close the pipework valves to isolate the pump 4 Ensure allauxiliaryservices such as heating cooling tanks supply etc are isolated 5 If the pump...

Page 17: ...ward on the proportional controlvalveandslowlyincrease by pushing the handle tofull pump speed Whendrivenelectricallystartthe systemand slowly increasethe speed withthehandwheelonthebeltvariator Using...

Page 18: ...the seal continues to leak at pressures below 145 psi it is an indication that the primarysealmaybe permanently damaged and should therefore be replacedattheearliestopportunity Checking the oil seals...

Page 19: ...anynoxious hazardous products havebeenpumped Isolate pump drive unit from all power and control supplies Close pipework valves to isolate the pump Disconnect the pump from the drive unit Secure The pu...

Page 20: ...nsert a plastic block between the two rotors 13 to stop them turning 2 Using a spanner remove the rotor nuts 9 These nuts have right hand threads 3 Therotorscan beremovedfromtheshafts 28 29 by hand or...

Page 21: ...andpress outtheoilseal 41 Itis essential to renew the oilseal upon re assembly 4 Remove the gasket 17 8 10 Removing the timing gears 1 Pull the rear inner bearing races 39 off the shafts A puller or e...

Page 22: ...haft lightly tap each end of the shaft with a soft malletandrotate Check the torque required to turn the shaft in the bearings The bearings are correctly adjusted when the torque to turn each shaft is...

Page 23: ...rence by adding or removing shims 30 between the gear face andshaftshoulderasindicatedinthe diagram Fullytighten the gear retaining nuts and check the clearances are within the specification limits If...

Page 24: ...eeve 9 Fitthesleeves ontotheshafts ensuringthat the drive pins locate in any other position than themissingspline 10 Fitthesealsleeveretainingclips 64 onto theshafts 11 Fit the rotorcase 11 and retain...

Page 25: ...the O ring 10 3 To remove the seal housing 1 Remove the gland guards 21 2 Thoroughly clean the inside and outside of the seal area on the rotorcase and the bores of the rotor 3 Remove theproduct O rin...

Page 26: ...ng Seal Face Static Seal Face Rotary Wave Spring 11 2 Single mechanical seal removal 1 Remove the gland guards 21 2 Thoroughly clean the inside and outside of the seal area on the rotorcase and the bo...

Page 27: ...engage correctly 5 Press therotating faces 83 intotherotor bores ensuring the drive pins locate correctly 6 Position the seal housing loosely in the rotorcase with the flat inside the rotor casealigne...

Page 28: ...ation a hydrostatic test of the heating system is recommended Hydrostatic test pressure water 90 psi Maximum working pressure 55 psi Heating tanks should be in operation approximately 15 minutes prior...

Page 29: ...l in the system ensure there is no pressure in the pump head 2 Clean the outside of the pump and valve casing 3 Remove the nuts 60 and housing 54 Loosen the nuts equally in order to move the housing a...

Page 30: ...14 Faults causes and remedies...

Page 31: ...ended torque settings in lbft Description Pump ToolSizes STP125 Frontcovernut 30 19mm Rotorcaseretainer 30 16mm Rotornut 110 41mm Bearinghousingscrew 33 8mm Allen Relief valve nut 15 14mm Footscrew 75...

Page 32: ...STP125 Pump Model Exploded View Drawing 16 Exploded view drawing and parts list 41 i i i i i i i i i i i 1 STP125 Page 30...

Page 33: ...ARD GLAND FP2000 STP125 2 521143202 22 SOCKET HD CAPSCREW M8x16mm 316 STAINLS 4 126008216 23 TIMING GEAR SET FP2000 STP125 1 529000208 24 TIMING GEAR SET FP2000 STP125 1 529000208 28 SHAFT DRIVEN STP1...

Page 34: ...G STP125 2 518081209 42 SEAL SLEEVE O RING VERSION STP125 2 516041214 43 O RING ROTOR STP125 NBR Viton PTFE 2 522001246 522011242 522031207 45 O RING SHAFT STP125 NBR Viton PTFE 2 522001247 522011243...

Page 35: ...BR Viton PTFE 2 522001250 522011241 522031206 45 O RING SHAFT STP125 NBR Viton PTFE 2 522001247 522011243 522031208 64 CLIP SHAFT SLEEVE RETAINER STP125 2 518081203 65 O RING HOUSING STP125 NBR Viton...

Page 36: ...MP 65 PSI RELIEF VALVE 1 517022201 57 ANCHOR PLATE SS FOR RELIEF VLV STP125 1 532120201 58 SEAL DIAPHRAGM FP2000 STP125 PTFE NBR PTFE Viton 1 513132200 513132201 59 STUD M10 1 5 x 40MM LG S S STP125 4...

Page 37: ...SKT HD ISO 8 8 M12 x 30mm PLTD 4 130112030 68 KEY RND END 10MM X 8MM X 63MM 1 199050209 69 SHAFT DRIVE KEYED STP125 1 504033216 72 HEATING TANK FOR ROTORCASE SS STP125 2 500030210 73 CAPSCREW SKT HD M...

Page 38: ...TING RING STP125 2 518081209 42 SEAL SLEEVE LIP SEAL VERSION STP125 2 516041215 43 O RING ROTOR STP125 NBR Viton PTFE 2 522001246 522011242 522031207 45 O RING SHAFT STP125 NBR Viton PTFE 2 522001247...

Page 39: ......

Page 40: ...For additional information contact your local representative or visit www contactgd com compressors 2015 Gardner Denver Inc Printed in U S A...

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