Dover MIDLAND A-1402C Series Instruction manual

Installation, Operation & Maintenance Manual
www.midland.com
Part No.: A-1402C, Rev. 1.3
Issue Date: May 2, 2022
Supersedes: A-1402C, Rev. 1.2 (Sept. 27, 2016)
External-Style Pressure Relief Valve
A-1402C Series
Installation, Operation
& Maintenance (IOM) Manual

Installation, Operation & Maintenance Manual
2External-Style Pressure Relief Valve A-1402C Series
SECTION 1 | INTRODUCTION.......................................................................................................................................... 4
1.1 Technical Specifications .................... .............................................................................................................. 4
1.2 Valve Perspectives ............................................................................................................................................. 6
1.3 Pre-Installation Regulations / Requirements................................................................................................... 8
1.3.1 Regulations........................................................................................................................................... 8
1.3.2 Safety Precautions ............................................................................................................................... 8
1.3.3 Precautions for Mounted-Valve Repair .............................................................................................. 8
1.3.4 Required Tools ..................................................................................................................................... 9
SECTION 2 | VALVE INSTALLATION.............................................................................................................................. 10
2.1 Preliminary Considerations ..........................................................................................................................10
2.2 Procedure .......................................................................................................................................................10
2.3 Leak Inspection ...............................................................................................................................................12
2.4 Valve Operation Notes and Precautions ......................................................................................................12
SECTION 3 | VALVE DISASSEMBLY.............................................................................................................................. 13
3.1 Procedure .......................................................................................................................................................13
SECTION 4 | VALVE INSPECTION ................................................................................................................................. 16
4.1 Inspection Procedures ................................................................................................................................... 17
4.1.1 Top Guide............................................................................................................................................17
4.1.2 Adjusting Screw Threads ..................................................................................................................17
4.1.3 O-Ring Retainer Grooves ................................................................................................................... 17
4.1.4 Valve Body ......................................................................................................................................... 17
4.1.5 Plug...................................................................................................................................................... 18
4.1.6 Sealing Surface (Valve Mounting) ...................................................................................................18
4.1.7 Valve Spring ........................................................................................................................................ 19
4.1.8 Spring Guide ...................................................................................................................................... 19
4.1.9 Rupture Disc ....................................................................................................................................... 20
4.1.10 Rupture Disc Flange ..........................................................................................................................20
4.1.11 O-Rings................................................................................................................................................21
4.1.12 Special Inspection Considerations.....................................................................................................21

3
External-Style Pressure Relief Valve A-1402C Series
SECTION 5 | VALVE ASSEMBLY ................................................................................................................................... 22
SECTION 6 | SPECIAL GUIDELINES AND PRECAUTIONS ON PRESSURE TESTING AND ADJUSTMENT ..................... 23
6.1.1 Determining Applicable Pressure Values ....................................................................................................23
6.1.1 Test Stand and Gauge Requirements ..........................................................................................................23
SECTION 7 | VALVE PRESSURE TESTING PROCEDURE ................................................................................................ 24
7.1 Without Rupture Disc Installed ...................................................................................................................24
SECTION 8 | VALVE ADJUSTMENT PROCEDURE.......................................................................................................... 25
8.1 Procedure Without Rupture Disc Installed ..................................................................................................26
8.2 Valve Pressure Testing Procedure With Rupture Disc Installed ................................................................26
8.3 Post-Test Procedure .......................................................................................................................................27
SECTION 9 | MAINTENANCE ....................................................................................................................................... 28
9.1 Prior to Maintenance Tasks Performed ....................................................................................................... 28
9.1.1 Retesting of Valves in Storage .......................................................................................................28
SECTION 10 | WARRANTY............................................................................................................................................ 28

Installation, Operation & Maintenance Manual
4External-Style Pressure Relief Valve A-1402C Series
1.0 INTRODUCTION
The A-1402C Series External-Style Pressure Relief Valves are corrosion-resistant safety valves improved to include redundant seals
to atmosphere, eliminating potential leak paths and further increasing the long life and reliability in Chlorine transportation.
• Corrosion-resistant materials provide maximum protection from wet Chlorine
• Successfully used in Chlorine and AHCL applications
• Triple seals on all potential leak paths to atmosphere
1.1 TECHNICAL SPECIFICATIONS
Figure 1-1 Valve Specifications

5
External-Style Pressure Relief Valve A-1402C Series
Valve Model Rupture Disc
Setting (PSIG)
Flow Rate @ 10%
> R.D. Setting
(SCFM)
Minimum Vapor
Tight Pressure
(PSIG)
Minimum Vapor
Tight Pressure
(PSIG)
A-14377C-ML 375 7070 356 285
A-14227C-ML 225 4367 213 171
Valve Model Outer Spring Inner Spring Name Plate Adjusting Screw
Part #
Rupture Disc
Part #
A-14377C-ML 15-375-SS 14-13-SS 14-377-ML-C 15-112-SS 14-23-TA-375-F
A-14227C-ML 15-150-MO 14-13-SS 14-227-ML-C 15-11-SS 14-23-TA-225-F
Table 1-1 Technical Specifications Per Valve Model

Installation, Operation & Maintenance Manual
6External-Style Pressure Relief Valve A-1402C Series
Figure 1-2 Exploded View
1.2 VALVE PERSPECTIVES

7
External-Style Pressure Relief Valve A-1402C Series
Figure 1-3 Cross-Sectional View with Callouts
Item Qty. Part Name
1 1 Top Guide
2 1 Stem
3 1 Plug
4 1 Body
5 1 Outer Spring
6 1 Follower
7 1 Guide
8 1 Top Nut
9 1 Top Gasket
10 1 Shaft Seal
11 1 Adjusting Seal
12 1 Seal Retainer
13 1 Inner Spring
14 1 Cap
15 1 Seal Screw
16 4 Stud
17 4 Nut
18 1 Wire Seal
19 1 Retainer
20 1 Seat O-Ring
21 1 Plug O-Ring
22 1 Flue O-Ring
23 1 Rupture Disc
24 1 Flue
25 8 Rupture Disc Flange Bolts
26 1 Rupture Disc Flange
27 1 Purge Valve
28 1 Name Plate
29 1 Protective Cap/Chain
30 1 Flange O-Ring (inner)
31 1 Flange O-Ring (outer)
32 1 Filler Gasket

Installation, Operation & Maintenance Manual
8External-Style Pressure Relief Valve A-1402C Series
1.3 PRE-INSTALLATION REGULATIONS / REQUIREMENTS
1.3.1 Regulations Midland External-Style 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. Regulations of other governmental bodies must be complied with
for stationary and mobile applications. All personnel should be familiar with and follow these regulations. Nothing
in these instructions is intended to conflict with or supersede these regulations. The information in this document
was gathered from knowledgeable sources, but Midland Manufacturing Corporation makes no representations or
guarantees about its accuracy or completeness and assumes no liability for this information.
Specifications are subject to change without notice.
1.3.2 Safety Precautions Midland valves are used in connection with a variety 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 instructions carefully before proceeding.
1.3.3 Precautions for Mounted-Valve Repair When performing maintenance on a pressure relief valve that is
mounted on a railcar, observe the following precautions.
• Wear protective clothing and equipment suitable for withstanding the materials to which you may be exposed
• Position yourself on the upwind side of the valve when possible
• Work with a partner who can help you in the event of an emergency
• Follow approved safety precautions for hazardous or toxic materials
CAUTION: Toxic Hazard. Always use extreme caution and proper equipment when involved with hazardous
materials. To avoid exposure to toxic or hazardous materials, make sure the tank car is empty and clean, and that
the work area is free of hazardous chemicals before removing or installing any valve.
WARNING: These external-style pressure relief valves are spring-loaded assemblies with a large amount of
stored potential energy in the spring. Handle with care to avoid damage to the valve stem, which could result in
breakage and ejected piece parts.
WARNING: When assembling or disassembling the valve, DO NOT position oneself directly in front of the spring
and stem. Instead, position oneself to the side away from the valve. Unexpected component failure – valve-stem
or spring breakage – may cause a sudden energy release that can discharge component parts a short distance in
an uncontrolled manner. Personal injury may be a result.
CAUTION
WARNING
WARNING

9
External-Style Pressure Relief Valve A-1402C Series
1.3.4 Required Tools
Before arriving at the installation site obtain the required tools and supplies prior to performing the procedures
indicated in this guide.
Tongue Mounting
Figure 2-1 Gasket-Sealing Surfaces
Recommended Wrenches
SAE Component Torque (ft.-lbs.) Item #
5/16” Hex 3/8” Rupture Disc
Flange Bolt 25 25
9/16" 1/2" Top Guide Nut 50 17
1-1/2" 1" Top Lock Nut 45 8
1/2" 1/8" NPT Needle Valve Wrench Tight 27
1-1/16"
Flats on Small Valve
O-ring Retainer, 5/8"
Mounting-stud Nuts
1-1/4"
Flats on Large Valve
O-ring Retainer, 3/4"
Mounting-stud Nuts
Table 1-2 Required Tools
Other Tools and Supplies
Screwdrivers Pipe Wrench
Wheel Puller Lint-free Cloth
Silicone Grease (or equivalent lubrication) Emery Paper (400 grit, cut in 1" strips)
Torque Wrench Wire Brush
Table 1-3 Additional Recommended Tools & Supplies

Installation, Operation & Maintenance Manual
10 External-Style Pressure Relief Valve A-1402C Series
2 VALVE INSTALLATION
2.1 PRELIMINARY CONSIDERATIONS
2.1.1 New valves are tested, adjusted and sealed at Midland. If a new valve
has been left in its original packaging, is undamaged and is not more
than six months old, it may be installed on a tank car without retesting
or recalibration.
2.1.2 Prior to installation, ensure that the valve remains clean and that the
gasket-sealing surfaces (Figure 2-1) are not damaged.
2.2 PROCEDURE
2.2.1 Remove the old valve and then insert a soft rubber plug into the tank
opening to prevent debris from entering the tank during cleaning of
the valve-mounting groove and studs on the manway cover plate.
2.2.2 Wire brush the threads of the mounting studs to remove rust or scale.
Nuts should move freely on clean studs. Studs should not exhibit excessive
corrosion.
2.2.3 Remove and discard all used gasket material.
2.2.4 Using a lint-free cloth and appropriate cleaning solvent, wipe clean the valve and cover plate sealing surfaces and the
mounting-stud threads.
2.2.5 For tongue-and-groove mountings, examine the sides of the groove. Because the valve tongue fits tightly into the
groove, any peening-over of the edges of the groove may make it difficult to properly fit the valve tongue into the
groove. If the sides of the groove are peened over, make corrections to meet the AAR groove tolerances.
2.2.6 Install the new gasket. Ensure it is fully seated. When a groove gasket is fully seated, 1/16" of free space should
remain above the gasket to permit locating and entry of the valve tongue.
Figure 2-1 Gasket-Sealing Surfaces
CAUTION: Groove Damage. In order to avoid groove damage, do not scratch the metal in the bottom of the
groove when removing the old gasket.
CAUTION: Do not use a sharp tool to press the new gasket into place or gasket damage may result.
CAUTION
CAUTION