COBREX®Storage Water Heater
9
PV500-65 04/15
4.5 Heat Exchanger Pressure Relief Valve Piping
The COBREX®heat exchanger is supplied with a pressure relief valve sized in accordance with the ANSI/ASME
Boiler and Pressure Vessel Code, Section VIII. The relief valve must be threaded directly into the dedicated relief
valve fitting located near the top of the heat exchanger and each relief valve discharge must be separately plumbed
to an appropriate floor drain. The discharge line must not be smaller than the relief valve opening, must allow
complete drainage of the valve and line and it must be positioned in the floor drain, such that water or steam
forcefully exiting the drain line does not openly splash.
The water heater must not be operated without a correctly installed, properly sized and properly operating relief
valve. If a replacement relief valve is required, it must be of the same type, pressure rating, and relieving capacity as
the original relief valve supplied with the water heater.
Do not plug or restrict the relief valve or the relief valve drain line.
It is strongly recommended that the relief valve(s) should be manually operated at least once a year. If water does
not freely flow from the manually operated relief valve or if it does no fully reseat when released, the relief valve must
be replaced with a new relief valve with the same ratings.
WARNING: Do not install a reducing coupling, valve or other restriction between the relief valve discharge
and a suitable floor drain. Such restriction could prevent the valve from fully relieving if the pressure
settings are exceeded, which could result in property damage, personal injury or death.
WARNING: Secure the relief valve piping to a suitable floor drain such that very hot water does not openly
splash during a significant relief valve discharge. If the relief valve pipe is not routed and secured to a
suitable drain, hot water discharge can result in property damage, scalding and personal injury or death.
4.6 Steam & Condensate Connections
1. All steam supply lines should be flushed before connecting the unit. Failure to flush lines could cause
components of unit to malfunction.
2. Steam supplied to the COBREX®storage water heater must not exceed 15 psi. If the steam supply pressure
exceeds 15 psi, a steam pressure regulating valve must be used to limit steam supply pressure to 15 psi.
WARNING: Steam supply to the heat exchanger must be constant and less than or equal to 15 psi. An
unregulated steam supply or steam supply in excess of 15 psi could cause loss of temperature control
and failure of heater components that may result in property damage, personal injury or death.
3. This water heater will perform in accordance with the steam and domestic water temperatures and flows to
which it is connected. To obtain the desired performance, it must be installed to operate with the temperature
and flow conditions specified when selecting the appliance. In order to achieve rated hot water output, the
capacity of the steam supply system must exceed the heater requirements as stated on the heater decal.
4. The condensate trap controls the discharge of condensate based on the load on the heat exchanger and
prevents the discharge of live steam from the condensate trap outlet. Inadequate drainage of condensate can
adversely affect heat transfer and limit the performance of the water heater. Damage to the water heater
attributed to poor condensate drainage is not covered in the product warranty.
5. Install upstream of the steam header, a steam trap and a Y-strainer with a blow-down valve piped to a suitable
drain or condensate receiver plumbing to drain condensate that collects in the supply piping.
6. A steam pressure gauge and vacuum breaker must be installed in the steam piping near the appliance inlet and
downstream from the steam pressure regulating valve, if equipped.
7. Connect the main steam trap(s) to the condensate return. The trap(s) must be located below the elevation of the
condensate drain connection on the heat exchanger.
8. Install a pressure gauge in the condensate line to confirm proper condensate lift.
9. Connect steam and condensate connections to the building system plumbing. The recommended methods of
condensate distribution are:
a. Plumb to a condensate receiver and pump or vacuum return to the condensate return header.
b. Plumb to a pneumatic/electric actuated condensate pump trap for return to the condensate return header.
c. Plumb to suitable drain (210ºF) – (Requires additional make-up water at steam supply boiler).
