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Doc. #: A-718C, Rev. 1 

Page 15 of 36 

5.1.3  Remove the outlet flange (item 30). If it is difficult to dislodge, screw a 1" threaded nipple about 10" long 

into the port. Move it back and forth gently to loosen the flange and work it off the valve body (item 4).  

Figure 5-4 Remove Outlet Flange 

5.1.4  Loosen the packing screw (item 7). Take care that any trapped chlorine fumes do not release on the person 

disassembling the valve. 

5.1.5  Using the hand wheel (item 1), lower the stem (item 2) so that the seal retainer (item 3) is below the sealing 

area of body (seat).  

Figure 5-7 Seal Retainer Below Body (Seat)

Figure 5-5 Loosen Packing Screw 

Figure 5-6 Lower Stem 

Summary of Contents for A-718C Series

Page 1: ...r A 718C Revision 1 Issue Date March 9 2017 Page 1 of 36 7733 Gross Point Road Skokie IL 60077 847 677 0333 Fax 847 677 0138 www midlandmfg com 1 Angle Valves A 718C Series Installation Operation Main...

Page 2: ...stallation Procedure 9 3 0 Operating Instructions 12 3 1 Valve Operation Notes and Precautions 12 4 0 Maintenance Instructions 13 4 1 Prior to Maintenance Tasks Performed 13 5 0 Valve Disassembly 14 6...

Page 3: ...and adjustable stem packing and soft self centering valve seat eliminates potential leak paths and further increasing the long life and reliability in Chlorine transportation Successfully used in Chl...

Page 4: ...cription Material Torque Value 6 Cap Screws 1 2 13 UNC 2B Monel 48 ft lb CS 38 ft lb 13 Top Nut 1 2 13 UNC 2B SS 20 ft lb 16 Hex Nut 3 8 16 UNC 2A Monel 22 ft lb CS 20 ft lb 19 Slotted Nut 7 18 20 UNF...

Page 5: ...Ring Stem 12 2 O Ring Flange 13 1 Lock Nut 14 4 Stud 15 4 3 8 Split Lock Washer 16 4 Hex Nut 17 1 O Ring 18 1 Retaining Pin 19 1 Slotted Nut 20 1 Male Packing Adapter 21 3 1 2 Split Lock Washer 22 1 O...

Page 6: ...Doc A 718C Rev 1 Page 6 of 36 Figure 1 3 Side View and Cross Sectional View with Callouts...

Page 7: ...is information Specifications are subject to engineering updates and may change without notice 1 4 2 Safety Precautions Midland valves are used in connection with a variety of products many of which a...

Page 8: ...2 Socket Wrench Top Nut SS 20 ft lb 27 N m 13 3 8 Socket Wrench Hex Nut Monel 22 ft lb 30 N m 16 CS 20 ft lb 27 N m 7 16 Socket Wrench Slotted Nut Inconel 38 ft lb 52 N m 19 SS 32 ft lb 43 N m 1 1 16...

Page 9: ...er plate Avoid scratching the metal in the bottom of the groove Discard the used gasket 2 2 4 Examine the sides of the groove to verify that there are no dents or burrs Since the valve fits tightly in...

Page 10: ...nately from 1 to 3 then 2 to 4 Do not tighten down too much on one side because this will shift the valve at an angle and may make it impossible to get a tight gasket seal 2 2 11 Torque the nuts accor...

Page 11: ...ormation in evaluating the valve s performance Fill in the appropriate information on this tag 2 2 14 A placard with an adhesive backing has been provided with each car set of valves This gives import...

Page 12: ...ve s Teflon seal making it difficult or impossible to close off If the valve is leaking at the seat inside the valve and you cannot stop it by a firm closing by hand of the hand wheel inform your supe...

Page 13: ...ion the Teflon seat has been deformed and needs immediate replacement Figure 4 1 Hand Wheel and Bonnet 2 If the top of the packing screw item 7 is within 3 8 of being flush with the yoke surface the v...

Page 14: ...down to ensure that the stem is neither bent nor binding in the threaded part of the bonnet item 5 Bent stems must be straightened to proceed with the disassembly 5 1 2 Remove the three 3 side port bo...

Page 15: ...t off the valve body item 4 Figure 5 4 Remove Outlet Flange 5 1 4 Loosen the packing screw item 7 Take care that any trapped chlorine fumes do not release on the person disassembling the valve 5 1 5 U...

Page 16: ...e retainer assembly retainer O ring and retainer seal washer Cut the Teflon seat seal out Do so with care as so the metallic retainer surface beneath is not damaged 5 1 7 Take off the four 4 bonnet nu...

Page 17: ...top surface of the insert Additionally ensure that the body assembly is supported by the body flange outer edges as so when the insert is being pushed out it can come out easily with its path being ob...

Page 18: ...27 CS This tool should also be used to remove the stem O rings item 11 the outlet O rings item 12 and insert O rings item 33 5 1 9 The seat surface of the insert is very critical and must be examined...

Page 19: ...ances are exceeded or the condition is questionable do not take a chance on it replace with a new part 5 1 10 Inspect the retainer assembly retaining pin item 18 retaining nut item 19 seal retainer as...

Page 20: ...inging of any parts is permitted excepted where noted herein By not observing these prohibitions that purchaser assumes full repsonsibility and liability for the proper functioning of the valves CAUTI...

Page 21: ...re they are free of pits scratches etc that could form leak paths The threads are 3 8 16 on top flange and 1 2 13 on side flange If any of the threads are stripped or corroded remove and replace the s...

Page 22: ...e outlet flange must be replaced Figure 6 6 Outlet Flange 6 1 8 Pipe Plug item 29 Using a wire brush clean the 1 NPT threads Inspect for worn rusted or galled threads The proper thread profile is a po...

Page 23: ...imensions are 2 245 0 003 inches OD by 1 505 0 003 inches ID If tolerances are exceeded or the condition is questionable do not to take a chance on it replace it with a new part Figure 6 9 Seat Insert...

Page 24: ...ooves and the bore where the seat inserts fit into the body Clean the side port where the outlet O rings and the outlet flange gasket seal 7 1 2 With a buffing wheel clean out the threads of the stem...

Page 25: ...inside threads the bore and the bottom flange face of the bonnet 8 1 2 Apply grease to the Acme thread and entire length of stem item 2 Screw it into the bonnet item 5 and run it up and down the full...

Page 26: ...o the bottom of the screw does not protrude below the threaded part of the bonnet Tighten the packing screw to 30 3 ft lb 40 4 N m to seat the Teflon packing rings Prevailing drag on the stem due to t...

Page 27: ...8 1 7 Lubricate interior of the body neck Insert packing spring into the neck of the body as shown Figure 8 11 Lubricate Body Neck Figure 8 12 Insert Packing Spring 8 1 8 Insert the male packing adap...

Page 28: ...on the top O ring then install the other one into the lower groove Be sure both O rings are properly installed in the grooves 8 1 10 Insert packing rings Ensure to the place the packing rings with the...

Page 29: ...line with the triangular outlet of the valve body as shown below 8 1 12 Grease the top flange studs item 14 on the body and put on the lock washers and nuts Using the appropriate sized wrench tighten...

Page 30: ...14 Tighten the packing screw to 30 3 ft lb 40 4 N m to seat the Teflon packing rings Prevailing drag on stem due to packing will be about 3 ft lb 4 N m Figure 8 21 Tighten Packing Screw 8 1 15 Apply...

Page 31: ...tem 32 and insert gasket 8 1 17 Grease the exterior surface of the seat insert and insert it into the body by pushing it down with the palm of your hang and slowly rotating it Figure 8 23 Grease Body...

Page 32: ...t be protected at all times 8 1 19 Try inserting the outlet flange item 30 without an O ring item 12 or gasket item 22 into the side port of the body It should go down all the way so that the facing f...

Page 33: ...22 Assemble the instruction plate item 23 hand wheel washer rounded edge facing upwards item 25 and hand wheel nut item 13 on the stem Ensure that the nut s plastic lock in on top Tighten nut Figure...

Page 34: ...1 Page 34 of 36 8 1 23 Install the outlet pipe plug item 29 in the outlet flange 8 1 24 Attach the chain to the body Figure 8 38 Install Pipe Plug Figure 8 39 Attach Chain to Body Figure 8 40 Secure...

Page 35: ...n the center of the tape and cover the hole with a little soap suds solution Any leak will result in bubbles forming at the hole 9 1 5 After the seat has been satisfactorily tested for no leakage thre...

Page 36: ...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 to Midland s...

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