604.8 Water pressure reducing valve or regulator. When connected to a public water supply system, an approved pressure-reducing
valve shall be installed in the building water service pipe near its
point of entrance to the building. Pressure to the building water
distribution piping shall be limited to a maximum pressure of 80 PSI
under no-flow conditions. The water distribution piping shall be relieved
of excessive pressure due to thermal expansion by one of the following
methods:
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1.
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Air chambers when equipped with an accessible means restoring
the air.
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2.
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Approved mechanical devices. Pressure at any fixture shall be
limited to no more than 80 PSI under no-flow conditions.
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Exceptions: Where the water service pipe supplies
water directly to:
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1.
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A water pressure booster system; or
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2.
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An elevated water gravity tank; or
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3.
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Pumps provided in connection with a hydropneumatic or elevated
gravity water supply tank system.
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Exception:
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(1)
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Instantaneous water heaters.
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(2)
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Well systems with water pressure tanks.
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