TITLE 4. THE PHILADELPHIA BUILDING CONSTRUCTION AND OCCUPANCY CODE
SUBCODE "M" (THE PHILADELPHIA MECHANICAL CODE)
SECTION M-702.0 DEFINITIONS
Pressure relief valve: A pressure-actuated valve held
closed by a spring or other means and designed to relieve pressure automatically
in excess of the device's setting.
* * *
Table M-703.4
HYDRONIC PIPE
|
Material
|
Standard
|
|
|
|
Acrylonitrile butadiene styrene (ABS) plastic pipe
|
ASTM D1527; ASTM D2282
|
|
Brass pipe
|
ASTM B43
|
|
Brass tubing
|
ASTM B135
|
|
Copper or copper-alloy pipe
|
ASTM B42; ASTM B302
|
|
Copper or copper-alloy tubing
(Type K, L or M)
|
ASTM B75; ASTM B88; ASTM B251
|
|
Chlorinated polyvinyl chloride
(CPVC) plastic
pipe
|
ASTM D2846; ASTM F441; ASTM F442
|
|
Cross-linked polyethylene/
aluminum/cross-linked
polyethylene (PEX-AL-PEX)
pressure pipe
|
CSA CAN/CSA-B-137.10
|
|
Cross-linked polyethylene
(PEX) tubing
|
ASTM F876; ASTM F877
|
|
Lead pipe
|
FS WW-P-325B
|
|
Polybutylene (PB) plastic pipe
and tubing
|
ASTM D3309
|
|
Polyvinyl chloride (PVC)
plastic pipe
|
ASTM D1785; ASTM D2241
|
|
Steel pipe
|
ASTM A53; ASTM A106
|
|
Steel tubing
|
ASTM A254
|
* * *
M-704.3.3 Soldered joints: All joint surfaces shall be
cleaned. A[n approved] flux conforming to ASTM B813 shall be applied. The joint
shall be soldered with a solder conforming to ASTM B32.
M-704.3.4
Solvent-cemented joints: Joint surfaces shall be clean and free from moisture.
An approved primer shall be applied to CPVC and to PVC pipe-joint surfaces.
Joints shall be made while the cement is wet. Solvent cement conforming to the
following standards shall be applied to all joint surfaces:
1. ASTM
D2235 for ABS joints.
2. ASTM F493 for CPVC joints.
3. ASTM
D2564 for PVC joints.
[CPVC joints shall be made in accordance with ASTM
D2846 listed in Chapter 21.]
Joints shall be made at acceptable ambient
temperatures as recommended by the solvent cement manufacturer.
* * *
M-707.1.2 Cutting or notching: A structural member shall
not be cut, notched or pierced [in excess of the limitations specified] except
as provided for in the building code [listed in Chapter 21, unless proven safe
by a structural analysis].
* * *
M-709.1 Where required: Shutoff valves shall be installed
in hydronic piping systems in the locations indicated in Sections M-709.1.1
through M-709.1.[6] 7.
M-709.1.1 Heat exchangers: Shutoff valves shall
be installed on the supply and return side of every heat
exchanger.
Exception: Shutoff valves shall not be required where heat
exchangers are: integral with a boiler; or are a component of a
manufacturer's boiler and heat exchanger packaged unit and are capable of
being isolated from the hydronic system by the supply and return
valves.
* * *
M-709.1.7 Zone: Shutoff valves shall be installed at each
zone and floor.
M-709.2 Reduced pressure: A pressure relief valve shall
be installed on the low-pressure side of a hydronic piping system that has been
reduced in pressure. The relief valve shall be set at the maximum pressure of
the system design. The valve shall be installed in accordance with Section
[M-605.0] M-709.2.1 and M-709.2.2.
M-709.2.1 Approval: All relief valves
shall bear the label of an approved agency. Relief valves shall have a minimum
rated capacity for the equipment served.
M-709.2.2 Discharge: The relief
valve shall discharge by gravity. Relief valve discharge pipes shall be of rigid
pipe that is approved for the temperature of the system. The discharge pipe
shall be the same diameter as the relief valve output. Relief valves shall not
discharge so as to be a hazard, a potential cause of damage or otherwise a
nuisance.
M-709.3 Access: Valves concealed within construction shall be
provided with access panels.