3.1.7.2
Globe Valves
Install globe valves so that the pressure will be below the disk.
Install
globe valves with the stems vertical.
3.1.7.3
Pressure-Reducing Valves
Provide compressed air entering each pressure-reducing valve with a
strainer. Provide each pressure-reducing valve unit with two block valves
and with a globe or angle bypass valve and bypass pipe. Provide a bypass
around a reducing valve of reduced size to restrict its capacity to
approximately that of the reducing valve. Provide each pressure reducing
valve unit with an indicating gage to show the reduced pressure, and a
safety valve on the low pressure side. These requirements do not apply to
small pressure regulating valves used to adjust pressure for pneumatic
equipment.
3.1.8
Hangers and Supports
**************************************************************************
NOTE: See NAVFAC P-355, "Seismic Design for
Buildings," Chapter 10, "Mechanical and Electrical
Elements," for calculating pipe support spacing for
schedules not shown. Delete Table I and reference
to seismic requirements if not required.
**************************************************************************
Selection, fabrication and installation of piping hangers and supports
shall conform to MSS SP-58, MSS SP-69, and MSS SP-89 [except that spacing
of the hangers and supports shall be as per Table I.] [Provide seismic
restraints for piping in accordance with PPIC Seismic Restraint.]
TABLE I. MAXIMUM SPAN FOR PIPE (METERS)
__________________________________________________________________________
STD. WT.
EX. STRONG
COPPER
COPPER
STEEL PIPE
STEEL PIPE
TUBE TYPE
TUBE TYPE
DIAMETER
SCHEDULE 40
SCHEDULE 80
K
L
MM
__________________________________________________________________________
15
1.50
1.50
1.10
1.00
--------------------------------------------------------------------------
20
1.75
1.75
1.30
1.30
--------------------------------------------------------------------------
25
2.00
2.00
1.50
1.45
--------------------------------------------------------------------------
40
2.30
2.35
1.75
1.70
--------------------------------------------------------------------------
50
2.60
2.60
2.00
2.00
--------------------------------------------------------------------------
65
2.80
2.90
2.20
2.10
--------------------------------------------------------------------------
80
3.10
3.20
3.35
2.30
--------------------------------------------------------------------------
90
3.35
3.35
2.50
2.50
--------------------------------------------------------------------------
100
3.50
3.60
2.75
2.70
--------------------------------------------------------------------------
125
3.90
3.90
3.05
2.90
SECTION 15211N
Page 28
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