WHITTAKER CONTROLS, INC.
A MEGGITT PLC COMPANY
INSTALLATION AND OPERATION MANUAL
PRESSURE TRANSDUCER SPOOL ASSEMBLY
C327598 CC327599 CC327600
INDUSTRIAL PRODUCTS GROUP Revision 1.1 12/01/2003 Page 7
DESCRIPTION AND OPERATION
1. Description (Refer to Figure 1)
A. The Pressure Transducer Spool Assembly (spool) consists of a straight pipe section with bolt
flanges. It is used to connect components of a fuel metering system for a turbine engine. The
spool includes a piezometer ring with a pressure sense NPT port which may be connected to a
suitable pressure measuring device to accurately monitor the fuel pressure in the upstream line.
B. The spool types covered in this manual are as follows:
Gas Metering Valve Inlet Spool – Part Numbers C327598 and C327598-1 (2 Inch Outlet)
Gas Metering Valve Outlet Spool – Part Numbers C327599 and C327599-1 (1-1/2 Inch Outlet)
Gas Metering Valve Outlet Spool – Part Number C327600 (2 Inch Inlet)
2. Operation
A. The pressure of the gas fuel flowing through the line upstream of a fuel metering valve may be
accuratelymonitoredbyconnectingasuitablepressuremeasuringdevice tothepiezometer ring
pressure sense port of the spool. The ring consists of eight pressure tappings equally spaced at
45° intervals round the circumference of the pipe section. They are joined by the circular ring
which is connected to the pressure measuring device. By this means, false readings due to
irregular flow can be avoided. If the pressure on one side of the pipe is relatively high, the
pressure on the opposite side is generally correspondingly low; with the piezometer ring a mean
value is obtained.
B. For P/N C327599 and C327599-1, the piezometer ring is part of the outlet flange.
C. For P/N C327600, the spool configuration is based on the part numbering system defined in
Figure 1, Sheet 3. For complete details of the features available, refer to Figure 1, Sheet 3.
3. Leading Particulars (Refer to Table 2)
