Emerson Crosby JLT*-JBS-E Series

WARNING
Suitability of the material and product for
the use contemplated by the buyer is the
sole responsibility of the buyer. Also storage,
installation and proper use and application
are the sole responsibility of the purchaser.
Emersondisclaims any and all liability arising out
of the same.
Any installation, maintenance, adjustment,
repair and testing performed on pressure
relief valves should be done in accordance with
the requirements of all applicable codes and
standards under which those performing such
work should maintain proper authorization
through appropriate governing authorities.
No repair, assembly and test work done by
other than Emerson shall be covered by the
warranty extended by Emerson to its customers.
You assume full responsibility for your work. In
maintaining and repairing Crosby products you
should use only parts manufactured by Emerson.
Call your nearest Emerson regional sales office or
representative for a service engineer should you
wish assistance with your field needs.
TABLE OF CONTENTS
1 Introduction ................................................... 4
2 Storage and handling .................................... 4
3 Installation ..................................................... 4
4 Hydrostatic pressure tests ........................... 5
5 Setting, testing and adjustments ................. 6
6 Valve maintenance ...................................... 10
7 Style variations ............................................ 21
8 Service records ............................................ 21
9 Spare parts .................................................. 21
10 Trouble shooting pressure relief valves .... 21
11 Emerson’ field servicesandrepair
programs ..................................................... 22
ATTENTION
The safety of lives and property often depends on
the proper operation of the pressure relief valves.
Consequently, the valves should be kept clean and
should be tested and reconditioned periodically to
make sure they function properly.
Emerson.com/FinalControl
CROSBY STYLE JOS-E, JBS-E, JLT*-JBS-E, JLT*-JOS-E VALVES
InstallatIon and MaIntenance InstructIons
© 2017 Emerson. All Rights Reserved. VCIOM-06208-EN 18/02
Engineering Doc. #IS-V3137B
Before installation these instructions must be read fully and understood

Emerson Crosby JLT*-JBS-E Series Specifications

General

Brand	Emerson
Model	Crosby JLT*-JBS-E Series
Category	Control Unit
Language	English

Summary

3 INSTALLATION

3.3 Inlet Piping

Guidelines for proper inlet piping installation to ensure valve function.

3.4 Outlet Piping

Recommendations for outlet piping design and installation for safe discharge.

4 HYDROSTATIC PRESSURE TESTS

4.1 Hydrostatic Test of Vessel or System

Procedures for hydrostatically testing vessels or systems with valves installed.

4.2 Hydrostatic Test of Outlet System

Considerations for hydrostatic testing of the outlet piping system.

5 SETTING, TESTING AND ADJUSTMENTS

5.1 New Valves

Information on factory testing and pre-installation checks for new valves.

5.7 Set Pressure Changes

Procedure for changing set pressure, including spring replacement.

5.8 Set Pressure Adjustment

Step-by-step instructions for adjusting valve set pressure.

5.9 Nozzle Ring Settings

5.10 Cold Differential Test Pressure Adjustments

5.11 SEAT LEAKAGE TESTS

5.11.1 Test Procedure

Procedure for determining seat tightness according to API standard 527.

5.11.3 Procedure

Detailed steps for performing the seat leakage test.

5.11.4 Tightness Standard

Defines acceptable leakage rates for metal and soft-seated valves.

6 VALVE MAINTENANCE

6.2 Disassembly

Step-by-step instructions for disassembling Crosby JOS-E/JBS-E valves.

6.2.1 Remove Cap and Cap Gasket

6.2.2 Remove Nozzle Ring Set Screw

6.2.3 Release Spring Load

6.2.5 Remove Bonnet Studs

6.2.6 Lift Bonnet

6.2.7 Remove Spring and Washers

6.2.8 Disc Holder and Insert Removal

Detailed steps for removing disc holder and insert for various orifice sizes.

6.2.13 Nozzle Ring and Nozzle Removal

Instructions for removing the nozzle ring and nozzle from the valve body.

6.4 Inspection

6.5 Reconditioning of Valve Seats

Procedures for reconditioning valve seats, including lapping.

6.5.2 Machining of Nozzle Seats

Guidelines for machining nozzle seats to restore flatness.

6.5.3 Machining of Disc Insert Seats

Procedures for machining and lapping disc insert seats.

6.6 Assembly

Step-by-step instructions for assembling valve components after maintenance.

6.7 RESTRICTED LIFT VALVES

6.7.1 Limit Spacer Function

6.7.2 Determining Correct Spacer Height

6.7.3 Measuring Valve Lift

6.8 ASSEMBLY OF CAP AND LIFTING LEVER DEVICES

6.9 Soft Seat Construction

10 TROUBLESHOOTING PRESSURE RELIEF VALVES

10.1 Seat Leakage

Discussion of seat leakage as a common and detrimental valve problem.

10.1.2 Distortion From Piping Strains

10.1.3 Operating Pressure Too Close to Set Pressure

10.1.4 Chatter

10.1.5 Incorrectly Adjusting Lifting Gear

10.1.6 Other Causes of Seat Leakage

10.1.7 Corrosion