Table of Contents
Advertisement
Advertisement
Table of Contents
Related Manuals for Dover Midland A-720 Series
Summary of Contents for Dover Midland A-720 Series
- Page 1 Installation, Operation & Maintenance Manual Top-Transfer 2" Angle Valve A-720, A-721 and A-724 Series Installation, Operation & Maintenance Manual Part No.: A-720/A-721/A-721-B/A-724, Rev. 1.8 Issue Date: Jan 3, 2022 Supersedes: A-720/A-721/A-721-B/A-724, Rev. 1.7 www.midland.com...
-
Page 2: Table Of Contents
Installation, Operation & Maintenance Manual SECTION 1 | REGULATIONS AND SAFETY REQUIREMENTS ...................3 Regulations ................................ 3 Safety Warnings and Precautions ........................3 SECTION 2 | INTRODUCTION ............................4 Component Identification and Parts Listings ....................4 SECTION 3 | VALVE INSTALLATION..........................8 Installation and Required Tools ........................8 SECTION 4 | OPERATING PROCEDURE ..........................10 Opening the Valve ............................ -
Page 3: Section 1 | Regulations And Safety Requirements
1 REGULATIONS AND SAFETY REQUIREMENTS 1.1 REGULATIONS Midland angle valves are used in contact with a variety of products, many of which are hazardous materials. The acceptance and transportation of products are regulated by the DOT and AAR in the U.S.A., and in Canada by CTC and Transport Canada. -
Page 4: Section 2 | Introduction
Installation, Operation & Maintenance Manual 2 INTRODUCTION Tank cars equipped with the Midland A-720, A-721-B and A-724 Series Top-Transfer Angle Valves offer long-term reliability and ease of maintenance leading to more efficient operations. Applications include: • Liquefied Petroleum Gas (LPG) applications •... - Page 5 2.1 COMPONENT IDENTIFICATION AND PARTS LISTINGS (CONT.) A-721-B ITEM DESCRIPTION PART NO. MATERIAL HANDWHEEL 720-1-AL ALUMINUM STEM 720-2A-SS STAINLESS GASKET RETAINER ASSY 720-3-CS STEEL* BODY 721-42B-DI DUCTILE IRON SPRING, COIL 720-5-SS STAINLESS STEEL RETAINER COVER 720-6-CS STEEL* OUTLET FLANGE 720-71-CS STEEL PACKING SCREW W/ INSERT 720-8-CS...
- Page 6 Installation, Operation & Maintenance Manual Figure 2-1 A-720/A-721/A-724 Valve Dimensions & Component Identifications Top-Transfer 2" Angle Valves A-720, A-721, A-721-B and A-724 Series...
- Page 7 Figure 2-2 A-721-B Valve Dimensions & Component Identifications Top-Transfer 2" Angle Valves A-720, A-721, A-721-B and A-724 Series...
-
Page 8: Section 3 | Valve Installation
Installation, Operation & Maintenance Manual 3 VALVE INSTALLATION Keep the new Angle Valve in its original shipping container. This will ensure that it remains clean and will protect the gasket face from nicks and other damage. Prior to installation, ensure that the valve remains clean, and the gasket-sealing surfaces are not damaged. SAE WRENCH COMPONENT(S)/DESCRIPTION 7/16"... - Page 9 3.1.10 Wrench-tighten the nuts a little bit at a time, going alternately in a crisscross pattern, 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. 3.1.11 Torque the nuts to a level prescribed by your engineering department.
-
Page 10: Section 4 | Operating Procedure
Installation, Operation & Maintenance Manual 4 OPERATING PROCEDURE 4.1 OPENING THE VALVE NOTICE: Operation of the valve must conform with all applicable CTC, AAR, DOT specifications (Parts 173.31, 174.67, etc.), other governmental bodies, and the operating instructions of your company. NOTICE 4.1.1 Wrench-tighten the nuts a little bit at a time, going alternately in a crisscross pattern, from 1 to 3, then 2 to 4. -
Page 11: Section 5 | Valve Qualification
5 VALVE QUALIFICATION NOTICE: Whenever angle valves are retested, it is recommended that new O-rings be installed. The Teflon seat seal ® and packing should be replaced, if there is any question about their serviceability. All replacement parts must be obtained from Midland Manufacturing Corp. - Page 12 Installation, Operation & Maintenance Manual 5.1.3 BODY. Inspect the part for corrosive degradation, particularly in the seat, threads, packing sealing and the side port areas. Clean off these areas to be sure they are free of corrosion, contamination, pits, scratches, etc., that could form leak paths. The threads are 1/2"-13 for the valve on the side flange.
- Page 13 5.1.6 PACKING SCREW. The thread is 1¼"-12 on the valve. It must be clean and sharp without nicks, scratches, pits, and other defects that would strip or gall the thread when screwed into the body. Figure 5.1.6 Packing Screw 5.1.7 BOTTOM SPACER WITH WIPER: The outer surfaces of the spacer surfaces must be free of nicks, scratches, and pits.
- Page 14 Installation, Operation & Maintenance Manual 5.1.9 Special Inspection Considerations NOTICE: Repair work is limited to cleaning and polishing. NOTICE WARNING: Machining Not Allowed. Without consent from the valve manufacturer or car owner, machining, grinding, welding or other alterations to the valve seat or stem seat is not allowed per AAR M1002, Paragraph A3.11.1 of the Tank-Car Specifications.
-
Page 15: Section 6 | Valve Disassembly
6 VALVE DISASSEMBLY 6.1.1 Before valve disassembly, open and close the hand wheel to run the stem (item 2) up and down to ensure that the stem is neither bent nor binding in the threaded part of the body (item 4). Bent stems must be straightened to proceed with the disassembly. - Page 16 Installation, Operation & Maintenance Manual 6.1.4 Take off the four (4) side flange bolts and lock washers (items 15A and 15B, respectively). Figure 6-3 Remove flange bolts and washers 6.1.5 Carefully remove side outlet flange (item 7). It may be necessary to insert two (2) screwdrivers (180° degrees apart) between the flange and the valve body to pry it out.
- Page 17 6.1.6 Raise the hand wheel slightly to lift the gasket retainer (item 3). Rotate it so that the two (2) nuts (item 18) are facing out the side flange opening. Tighten down on the handwheel to keep the gasket retainer from rotating out of position. Nuts Figure 6-5 Rotate handwheel to view nuts 6.1.7...
- Page 18 Installation, Operation & Maintenance Manual 6.1.8 Raise the stem (item 2) up in the body as far as it will go. It now is possible to take the gasket retainer out of the valve. Needle-nose pliers may be helpful in gripping the gasket retainer to extract it through the side port opening. Retainer Figure 6-7 Remove retainer 6.1.9...
-
Page 19: Section 7 | Valve Reassembly And Testing Procedures
7 VALVE REASSEMBLY AND TESTING PROCEDURES 7.1 CLEANING NOTICE: Do not use solvents or grease lubricants that are incompatible with the products in the tank. For example, a petroleum-based grease may cause a chemical reaction when it comes in contact with chlorine. Contact your supervising engineer for suitable cleaning and lubricating material recommendations. - Page 20 Installation, Operation & Maintenance Manual (Item 14A) Valve Stem (Item 2) Washer (Item 14B) Handwheel (Item 1) Figure 7-2 Reassembly steps 7.2.8 through 7.2.10 7.2.8 From the bottom side of the body, insert the handwheel end of the stem (item 2). Screw the stem up until the handwheel flats clear the top of the packing screw;...
- Page 21 7.2.11 Retainer Reassembly Figure 7-3 Reassembly steps 7.2.11.1 through 7.2.11.3 7.2.11.1 Place gasket retainer (item 2) into a vice as shown. 7.2.11.2 Place seat seal (item 10) in the gasket retainer (item 2), place the seal washer on top of the seat seal as shown 7.2.11.3 Make sure seal washer is flat with the seat seal Figure 7-4 Reassembly steps 7.2.11.4 through 7.2.11.5...
- Page 22 Installation, Operation & Maintenance Manual Figure 7-5 Reassembly steps 7.2.11.6 through 7.2.11.7 7.2.11.6 Place the pin (item 19) into the hole as shown, tap the pin into place. 7.2.11.7 Place the retainer assembly into the fixture as shown Figure 7-6 Reassembly step 7.2.11.8 7.2.11.8 Use the handle of press fixture to insert the pin as shown in Figure 7-6 Top-Transfer 2"...
- Page 23 U-bolt and Retainer Nuts Gasket Retainer (item 18) Assembly (Item 3) Figure 7-7 Reassembly steps 7.2.12 through 7.2.15 7.2.12 Position the gasket retainer assembly into the valve body through the side port so that the seat seal (item 10) is resting on the body seat;...
- Page 24 Installation, Operation & Maintenance Manual Flange Bolts with Lock Washers (item 15) Outlet Flange (Item 7) Figure 7-8 Reassembly steps 7.2.16 through 7.2.21 7.2.16 Install the outlet O-ring (item 13) if on A-720/721/724 onto the outlet flange (item 7). Install the outlet gasket (item 13) if on A-721-B onto the outlet flange (item 7).
-
Page 25: Testing Procedure
If your company has an approved test procedure, follow it. If it does not, these procedures provide essential guidelines in regard to pressure testing. CAUTION: Safety Protection. Wear appropriate safety glasses or face-shield and protective clothing when conducting this procedure. Valve testing involves high-velocity air and water flow that can cause injury. CAUTION 7.3 TESTING PROCEDURE 7.3.1... -
Page 26: Section 8 | Maintenance
Installation, Operation & Maintenance Manual 8 MAINTENANCE NOTICE: It is essential to establish a periodic retesting and preventative maintenance program with angle valves. The DOT and AAR have set forth a retesting interval that should be considered the maximum length of time between tests. - Page 27 7733 Gross Point Road Skokie, IL 60077 Tel: (847) 677-0333 Fax: ( 847) 677 0138 www.midlandmfg.com...
Need help?
Do you have a question about the Midland A-720 Series and is the answer not in the manual?
Questions and answers