Groth 1721B User Manual
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TABLE OF CONTENTS
I. INTRODUCTION
3
II. DESIGN, FUNCTION & OPERATION
4
1. FIGURE 1 – TYPICAL TANK INSTALLATION
4
III. GENERAL SAFETY INSTRUCTIONS
5
IV. SAFETY
WARNINGS
5
V. INSPECTION AND INSTALLATION
6
1. TABLE 1 – STUD SELECTION
6
2. TABLE 2 – BOLT TORQUE CHART
6
VI. PREVENTATIVE
MAINTENANCE 7
VII. RECOMMENDED SPARE PARTS
7
1. TABLE 3 – RECOMMENDED SOFT GOOD SPARE PARTS
7
2. TABLE 4 – VALVE DIAPHRAGM USAGE
7
3. TABLE 5 – REPLACEMENT SPRING PART NUMBERS
7
VIII. DISASSEMBLY
8
1. TABLE 6 – STEM LENGTH
8
2. TABLE 7 – RECOMMENDED PALLET ASSEMBLY TORQUE
8
3. FIGURE 2 – PALLET ASSEMBLY DETAIL
8
4. FIGURE 3 – SPRING SETTING PROCEDURE
9
IX. VALVE
TESTING PROCEDURE
10
1. TABLE 8 – NOMINAL PALLET ASSEMBLY WEIGHT
10
X. MODEL
INFORMATION
11
XI. PRODUCT LIMITED WARRANTY
11
XII. APPENDIX A – MODEL 1721B PRESSURE/VACUUM RELIEF VALVE
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XIII. APPENDIX B – MODEL 1722B PRESSURE/VACUUM RELIEF VALVE
14
XIV. APPENDIX C – MODEL 1723A PRESSURE/VACUUM RELIEF VALVE
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XV. APPENDIX D – MODEL 1761A VACUUM RELIEF VALVE
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INTRODUCTION
The Groth Spring-Loaded Pressure / Vacuum Relief Valves (PV) are designed to protect tanks from damage caused
by overpressure or over vacuum conditions. By containing product vapors PV valves reduce costly product
evaporation losses due to normal tank breathing. In addition, atmospheric contamination is reduced by containing
product vapors until tank pressure reaches the set pressure of the PV valve.
All pallets include Groth's special "cushioned air" seating. Fluoropolymer seating diaphragms are standard; they
minimize sticking caused by resinous vapors and atmospheric moisture. The valve has a self draining housing body
and drip rings to protect seating surfaces from condensate and freezing. This design also avoids dangerous pressure
or vacuum buildup due to binding or clogging of the vent. Diaphragms are available in Fluoropolymer, Buna-N, FKM
and other elastomers; metal-to-metal seat can be provided when required.
To insure the proper alignment of seating surfaces, there is both peripheral and stem pallet guidance. As with all
Groth products, every spring loaded valve is factory inspected and tested.
Pressure and Vacuum Relief Valves are preset at the factory in accordance with the purchase order. These settings
are printed on the stainless steel name tag.
All PV valves require regular inspection and preventative maintenance. The frequency of inspection depends upon
installation/use conditions. The valve must be maintained by a knowledgeable valve technician. It should only be
assembled under clean conditions - preferably in a shop environment. Carefully read and understand this Manual
before installing or repairing this valve.
For information not contained in this manual, please contact:
Groth Corporation
13650 N. Promenade Blvd
Stafford, TX 77477
281-295-6800 (Phone)
281-295-6995 (Fax)