3.4.3 Student Book © 2004 Propane Education & Research CouncilPage Bulk Plant Emergency Shutdown Equipment and Periodic Examination Methods One of the leading causes of accidental spills of propane is a pull-away at a transfer area. The term pullaway refers to an accident caused by a bobtail or transport “pulling away” from the transfer point while the hoses are still connected. A pull-away may break the hose or even pull out the piping network, creating a large propane leak and possible fire. To avoid these problems, most transfer areas use bulkheads and emergency shut-off valves (ESVs). In this module you will learn to identify: (1)Operating characteristics of bulkheads (2)Operating characteristics of emergency shut-off valves (ESVs)

3.4.3 Student Book © 2004 Propane Education & Research CouncilPages 1 & 3 Identifying Operating Characteristics of Bulkheads Bulkheads— are located where the plant hoses connect to a large piping network where transports & bobtails are loaded & unloaded. Bulkheads are normally made from steel beams and reinforced concrete, and often are surrounded by large steel or concrete posts to prevent vehicles from colliding with the critical piping. NFPA 58 and many state and local codes stipulate that a stanchion should be able to withstand a force from any direction sufficient to cause the worst mechanical or structural damage to be on the vehicle side of the transfer point. Bulkhead maintenance is limited to inspection of fittings, valves, and stanchions for structural integrity and propane leaks, especially in the event of a pull-away.

3.4.3 Student Book © 2004 Propane Education & Research CouncilPage 2 Identifying Operating Characteristics of Bulkheads Bulkheads Figure 1a. Vertical Bulkhead Figure 1b. Vertical Bulkhead

3.4.3 Student Book © 2004 Propane Education & Research CouncilPage 3 Identifying Operating Characteristics of (ESVs) Emergency Shut-Off Valves (ESVs) are (one type of) valves that may be used to automatically stop the flow of propane in the event of a pull-away. NFPA 58 requires that the valves be installed in the liquid or vapor lines of certain piping systems within 20 ft. of the junction of hose and rigid piping. In some plants, ESVs are often installed at the bulkheads for loading bulk trucks and unloading transports. In addition, they are installed at the hose junctions on tank car unloading risers.

3.4.3 Student Book © 2004 Propane Education & Research CouncilPage 3 Identifying Operating Characteristics of (ESVs) Emergency Shut-Off Valves (ESVs) New provisions for transfer area protection require the installation of ESVs to protect against hose failure resulting from a number of circumstances, including ruptures, exposure to fire, and pullaways. NFPA ESVs must incorporate a means of closing by: Manual shut-off at the valve location Manual shut-off from a remote station Automatic shut-off by thermal (fire) actuation

3.4.3 Student Book © 2004 Propane Education & Research CouncilPages 4 & 5 Identifying Operating Characteristics of (ESVs) Types Of Emergency Shut-Off Valves Mechanical Emergency Shut-off Valves a. With Dust Cover b. Cutaway Figure 2. Mechanical ESVs Courtesy of Rego Co.

3.4.3 Student Book © 2004 Propane Education & Research CouncilPage 6 Identifying Operating Characteristics of (ESVs) Mechanical Emergency Shut-off Valves— Because the main valve disc is spring loaded and directly in the propane flow path, the valve also functions as an excess flow check valve. Figure 3. Mechanical ESVs Courtesy of Fisher Controls Co.

3.4.3 Student Book © 2004 Propane Education & Research CouncilPage 7 Identifying Operating Characteristics of (ESVs) Mechanical Emergency Shut-off Valves Figure 4. Mechanical ESV-Vapor Application Courtesy of Rego Co.

3.4.3 Student Book © 2004 Propane Education & Research CouncilPages 7 & 8 Identifying Operating Characteristics of (ESVs) Mechanical Emergency Shut-off Valve Installations Figure 5a. Mechanical ESV Installations Courtesy of Rego Co.

3.4.3 Student Book © 2004 Propane Education & Research CouncilPages 7 & 8 Identifying Operating Characteristics of (ESVs) Mechanical Emergency Shut-off Valve Installations Figure 5b. Mechanical ESV Installations Courtesy of Rego Co.

3.4.3 Student Book © 2004 Propane Education & Research CouncilPages 8 & 9 Identifying Operating Characteristics of (ESVs) Mechanical Emergency Shut-off Valves with Pneumatic Operators Figure 6. Mechanical ESV with Pneumatic Operator

3.4.3 Student Book © 2004 Propane Education & Research CouncilPages 9 & 10 Identifying Operating Characteristics of (ESVs) Pneumatic Emergency Shut-off Valves – There are certain valves available today which are truly pneumatic ESVs; that is, the pneumatic operator is an integral, internal part of the valve. Figure 7a. Pneumatic ESV Courtesy of Fisher Controls Co.

3.4.3 Student Book © 2004 Propane Education & Research CouncilPage 10 Identifying Operating Characteristics of (ESVs) Pneumatic Emergency Shut-off Valves – There are certain valves available today which are truly pneumatic ESVs; that is, the pneumatic operator is an integral, internal part of the valve. Figure 7b. Pneumatic ESV Courtesy of Fisher Controls Co.

3.4.3 Student Book © 2004 Propane Education & Research CouncilPage 11 Identifying Operating Characteristics of (ESVs) Pneumatic Emergency Shut-off Valves Figure 8. Railcar/Pneumatic ESV Courtesy of Fisher Controls Co.

3.4.3 Student Book © 2004 Propane Education & Research CouncilPage 11 Identifying Operating Characteristics of (ESVs) Pneumatic Emergency Shut-off Valves Figure 8. Railcar/Pneumatic ESV Courtesy of Fisher Controls Co.

3.4.3 Student Book © 2004 Propane Education & Research CouncilPage 12 Identifying Operating Characteristics of (ESVs) Pneumatic Emergency Shut-off Valve Installations The pneumatic tubing can be charged (pressurized) in a number of ways. Figure 9 shows a typical charging system using nitrogen, air, or CO 2, which includes a cylinder, shut-off valve and regulator. Alternate means of charging could include an auxiliary charging line from the plant air compressors or a tap off the plant service air system. Any reliable source of pneumatic pressure is acceptable as long as it is filtered and regulated up to 50 psig.

3.4.3 Student Book © 2004 Propane Education & Research CouncilPages 13 & 14 Identifying Operating Characteristics of (ESVs) Emergency Shut-off Valve Maintenance Manufacturer's literature details the requirements and procedures for maintenance and repair. An annually documented test of the ESV is required by NFPA 58. ESVs should be inspected frequently for gas leakage at all body seams, plus the connections to piping and hose. The pneumatic control system should be checked frequently for proper operation; check for leaks by pressurizing the system and checking all connections with liquid leak detector or a soapy water solution. Conduct frequent tests of the closing feature of the ESVs under simulated conditions.

3.4.3 Student Book © 2004 Propane Education & Research CouncilPage 15 Identifying Operating Characteristics of (ESVs) Figure 11. Tank Car Unloading Riser

3.4.3 Student Book © 2004 Propane Education & Research CouncilPages 16 & 17 Time to See If You Got the Key Points of This Module… Complete the Review on page 16. See if you are ready for the Certification Exam by checking off the performance criteria on page 17.