Introduction; General Introduction; Main Valve Introduction; Pilot Valve Introduction - GE Baker Hughes 2900-40 Series Maintenance Manual

VIII. Introduction
A. General Introduction
"A pilot operated pressure relief valve is a pressure relief valve
in which the major relieving device is combined with and is
controlled by a self actuated auxiliary pressure relief valve." -
Source ASME Code, Section VIII-Div.1, Paragraph UG-126.
The Consolidated Pilot Valve (PV) is designed to provide
reliable performance characteristics and stable operation
within a pressure range of 15 to 3750 psig (10.34 to 2585.53
barg)
B. Main Valve Introduction
The Consolidated Pilot Operated Safety Relief Valve (POSRV)
cast bodies are designed to meet the often specified inlet and
outlet connection combinations. Sizes range from 1" - 8" (25.4
mm - 203.20 mm); pressure ratings from 150 - 2500 class.
The standard metal seat is the same design that has been
successfully utilized in the Consolidated SRV for over 50 years.
Capacities are certified by National Board of Boiler and
Pressure Vessel Inspectors and published in their NB18
entitled "Pressure Relief Device Certifications."
Main Valve Features
• Orifice controlled capacity
• Superior tightness
• Removable nozzles for replacement or remachining
• Standard O-Ring sizes: readily available, easily replaced
• National Board certified capacities
• Uses many parts standard on 1900 Series SRV
Model
39PV07, SS
39PV37, SS
Note: With the installation of the heat exchanger, temperature range may be expanded to 1200°F ( 648.9°C).
© 2019 Baker Hughes, a GE company. All Rights Reserved.
C. Pilot Valve Introduction
Standard pilot construction consists of 316SS parts with
nitrile O-Rings with Teflon based seals throughout. Alternate
materials can be provided by contacting the factory.
Pilot Valve Features
• One pilot fits all main valves
• Standard O-Ring seals
• Superior seat tightness
• Accurate adjustment of blowdown and set point
• Positive closure after blowdown
• Reduces icing and clogging
• Field test connection
• Remote Sensing
• External blowdown adjustments
Service and Applications
Main valve pressure and temperature limitations are
combined in pressure class categories according to ANSI
Standards. Conversely, the pressure and temperature limits of
the Pilot Valve are presented separately.
Note: When Replacing or Repairing the main valve and
Table 1: Service and Applications
Pressure Range
Service min.
psig
Steam 15
Steam 751
pilot valve assembly, pay particular attention to the
pressures and temperature limitations for both the
main valve and pilot valve to ensure compatibility.
max.
barg psig barg °F
1.03 750 51.71 -20
51.78 3750 258.55 -20
Consolidated 2900-40 Series POSRV Maintenance Manual | 15
Temperature Range
min. max.
°C °F °C
-20.0 505 262.8
-20.0 505 262.8