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P/N: A-22075/6, Rev. 1.1 

Page 6 of 45 

 

 

 

 

 

 

 

 

Item 

Qty. 

Part Name 

Top Guide with Insert 

Valve Stem 

Assembly Retainer 

Valve Body 

PRV Spring 

Follower 

Insert Locknut 

O-ring (2-431) 

O-ring (2-351) 

10 

Hex Nut 

11 

Hex-Head Cap Screw 

12 

Hex-Head Cap Screw 

13 

Name Plate 

14 

Drive Screw 

15 

Gasket 

16 

Wire-Seal Kit 

 

 

Figure 1-4 A-22075/A-22076 Valve Components

 

Summary of Contents for A-22075 Series

Page 1: ...0333 Fax 847 677 0138 www midlandmfg com Part Number A 22075 6 Rev 1 1 Issue Date July 25 2016 Supersedes A 22075 6 Rev 1 0 Internal Style Pressure Relief Valve A 22075 Series and A 22076 Series Inst...

Page 2: ...s and Precautions 12 3 0 Valve Disassembly 13 3 1 Procedure 13 4 0 Valve Inspection 19 4 1 Inspection Procedure 20 5 0 Valve Assembly 28 6 0 Special Guidelines and Precautions on Pressure Testing and...

Page 3: ...ethanol tank cars requiring high flow pressure relief High quality steel construction Triple seals on all potential leak paths to atmosphere Easy to replace seal design for ease of maintenance 1 1 Tec...

Page 4: ...P N A 22075 6 Rev 1 1 Page 4 of 45 Figure 1 2 A 22075 PI and A 22076 PI Valve Dimensions...

Page 5: ...P N A 22075 6 Rev 1 1 Page 5 of 45 1 2 Valve Perspectives Figure 1 3 A 22075 PI A 22076 PI Valve Exploded View...

Page 6: ...tem 3 1 Assembly Retainer 4 1 Valve Body 5 1 PRV Spring 6 1 Follower 7 1 Insert Locknut 8 1 O ring 2 431 9 1 O ring 2 351 10 2 Hex Nut 11 2 Hex Head Cap Screw 12 2 Hex Head Cap Screw 13 1 Name Plate 1...

Page 7: ...mbly Retainer 4 1 Valve Body 5 1 PRV Spring 6 1 Follower 7 1 Insert Locknut 8 1 O ring 2 431 9 1 O ring 2 351 10 2 Hex Nut 11 2 Hex Head Cap Screw 12 2 Hex Head Cap Screw 13 1 Name Plate 14 2 Drive Sc...

Page 8: ...of products many of which are hazardous materials and could cause serious injury or damage This valve should only be installed operated and maintained by qualified personnel Read all of these instruct...

Page 9: ...ets for all the commodities used with the associated valve 1 3 4 Required Tools Before arriving at the installation site obtain the required tools and supplies prior to performing the procedures indic...

Page 10: ...le Nuts should move freely on clean studs Studs should not exhibit excessive corrosion 2 2 3 Remove and discard all used gasket material CAUTION Groove Damage In order to avoid groove damage do not sc...

Page 11: ...valve having damaged sealing surfaces 2 2 8 Remove the rubber plug which was inserted in Step 2 2 1 from the cover plate 2 2 9 Position the valve gently into the mounting Align the body holes over th...

Page 12: ...esult in leaks at the valve mounting joint 2 4 Valve Operation Notes and Precautions NOTICE Operation of the valve must conform with all applicable TC AAR DOT specifications Parts 173 31 174 67 etc ot...

Page 13: ...attempt to disassemble the valve without first reading these instructions or injury may result Spring pressure must be adjusted to minimum and a bench clamp or press used for disassembly 3 1 1 Remove...

Page 14: ...ve the sealing gasket item 15 and dispose Figure 3 4 Remove Sealing Gasket 3 1 5 Loosen the locknut item 7 on the stem item 2 while holding the retainer in place See Table 1 2 for recommended wrench s...

Page 15: ...ove of the retainer Figure 3 7 Remove O rings from Retainer 3 1 8 Clean and lubricate the stem thread Loosen the locknut item 10 from adjustment nut item 10 using two wrenches of suitable length as sh...

Page 16: ...having a support block or floorboard to allow pass through of the valve stem 3 1 11 Using a press yoke having a cutaway as shown in Figure 3 10 compress the valve spring enough to allow loosening of...

Page 17: ...e press taking care to lift it by the threaded valve stem item 2 This will prevent the stem from falling out of the valve body WARNING Valve Seat Damage With spring pressure removed from the valve ste...

Page 18: ...oden block beneath the short end of the valve stem to prevent it dropping and damaging the valve seat 3 1 15 Remove the spring follower item 6 and the valve spring item 5 from the valve guide tube if...

Page 19: ...netic particle testing according to a qualified procedure by certified trained personnel Such testing is indicated within this document where mandatory Additionally specific inspections must be perfor...

Page 20: ...ncipally a structural part There should be no paint on the guide bushing of this part where the valve stem enters it or between adjacent surfaces of the top guide and valve body The area of discharge...

Page 21: ...alled threads and chase the threads with a thread die or replace stems with significant thread damage 4 1 2 4 The sealing surface is the stem seat Figure 4 4 Clean the stem seat with emery paper 400 g...

Page 22: ...1 The grooves Figure 4 6 must be free of gouge marks corrosion pits and rust Since the O rings must seal against these surfaces any irregularities can cause the valve to leak Clean the groove by sandi...

Page 23: ...ve to the mounting plate on the railcar Figure 4 8 Machining of this surface is permitted A good seating surface is necessary to ensure there are no leaks in this area Figure 4 8 Valve Body Sealing Su...

Page 24: ...2 minutes Remove from the press and then measure the spring free height If free height is less than the minimum indicated in Table 4 1 replace the spring WARNING Deficient Valve Travel Coil springs t...

Page 25: ...ds look for dents or gouged surfaces on the inside of the guide tube Repair the damage to allow free movement of the spring guide Figure 4 10 Spring Follower and Guide Tube WARNING Valve Sticking If t...

Page 26: ...ischarging fluid Inspect the guide tube by moving the top guide up and down the length of the guide tube as indicated below If it binds look for dents or gouged surfaces on the inside of the guide tub...

Page 27: ...nd nuts are 7 8 9 UNJ thread UNC nuts cannot be used 4 1 12 Special Inspection Considerations 4 1 12 1 Previous procedures may not cover all conditions encountered in the field Therefore it is the res...

Page 28: ...For valve assembly please see valve disassembly instructions Reassemble in the reverse order of those instructions For recommended torque specifications for A 22075 A 22076 Series valve reassembly pl...

Page 29: ...OTICE A popping pressure is not specified It is only necessary to ascertain the STD pressure as pressure is increased and to establish the vapor tight pressure as pressure is being reduced STD is defi...

Page 30: ...t these procedures provide essential guidelines in regards to pressure testing 7 1 Initial Setup 7 1 1 Install the valve on the test fixture and alternately tighten down all of the nuts Figure 7 1 Aff...

Page 31: ...the valve body with water to allow bubble detection at the valve seat Figure 7 3 Fill with Water 7 1 4 Take a position allowing observation of the pressure gauge and bubbling of air in the valve body...

Page 32: ...f of the STD pressure Then slowly increase the pressure 7 2 4 Observe the STD pressure and then bleed off the pressure slowly to observe the VTP 7 2 5 Repeat this procedure at least two 2 more times T...

Page 33: ...hese procedures provide essential guidelines in regards to pressure testing 8 1 Valve Setting Adjustment 8 1 1 Remove the wire seals from the spring adjustment nuts Figure 8 1 Remove Wire Seal 8 1 2 L...

Page 34: ...adjusting nut Figure 8 3 Loosen Locknut 8 1 4 Using a manual or an air operated press invert the valve to compress the spring and relieve pressure from the spring adjusting nut Use a tubular yoke Fig...

Page 35: ...ng the spring s load will frequently result in damaged stem threads 8 1 5 Apply indicator reference marks to the bottom spring adjusting nut and the spring follower and then loosen or tighten the spri...

Page 36: ...Based upon this calculation re compress the valve spring and alter the valve adjustment for the midpoint in the STD tolerance range STD Settings VTP Settings 75 psig 3 psig 60 psig minimum Table 8 1 S...

Page 37: ...ve to the test chamber vent the pressure in the test stand Remove putty and drain water Then remove the valve from the test fixture 8 2 2 Wipe or blow away any remaining soapsuds and water used in the...

Page 38: ...f the valve Be sure to mask the nameplate so that it will be readable afterward CAUTION Mounting Interference DO NOT paint the sealing surfaces of the valve that will contact the manway s cover plate...

Page 39: ...before attempting maintenance procedures Table 1 3 outlines some suggested tools that will be needed 9 2 Leak Repair on a Mounted Valve 9 2 1 Repair the retainer O rings Exception When performing that...

Page 40: ...olts items 11 and 12 and situate them so they won t be dropped or lost Figure 9 2 Remove Bolts and Set Aside for Later 9 2 5 Mark the top guide item 1 and body item 4 with a vertical line to allow the...

Page 41: ...r two screwdrivers 180 apart to quickly dislodge the O ring retainer 9 2 8 Remove the O ring retainer item 3 Remove the two 2 O rings items 8 and 9 from the retainer and inspect the O ring grooves Fig...

Page 42: ...O rings with another one containing non epoxied O rings If valve leakage exceeds the sealing capability of the O ring replace or rebuild the valve 9 2 13 For special guidelines and precautions on pres...

Page 43: ...alent to the AAR M1002 figures E19 14 through E19 23 for the valve being tested The pressure gauge must meet the requirements of D4 5 Test Gauge Standards and date tagged 9 2 15 Valve Testing Procedur...

Page 44: ...factory of a like quantity of product 2 refunding to purchaser money paid to Midland for its product or 3 issuance of written authorization for the Purchaser to repair or replace at costs comparable t...

Page 45: ...Copyright 2014 OPW Printed in USA 2014 Delaware Capital Formation Inc All Rights Reserved...

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