PVI Industries PV500-25 - Manual (Page 8)

QUICKDRAW

Steam Heater
8
PV500-25 06/12
5.2 Filling the Unit
1. Fill the system with water. To be sure that the unit is not “air bound,” open the relief valve. Leave the valve open
until a steady flow of water is observed. Close valve and complete filling the system.
2. In hard water areas, potable water treatment should be used to reduce introduction of minerals into the system.
Minerals in the water can collect on the tubes and heat-exchanger surfaces reducing the life of the product.
Heat exchanger failure due to scale accumulation is not covered by the product warranty.
3. Make sure there are no system leaks. DO NOT use petroleum based stop-leak products. All system leaks must
be repaired.
5.3 Relief Valve Piping
The water heater is supplied with a pressure and temperature relief valve, sized in accordance with ASME
requirements. Each relief valve should be piped to a suitable floor drain. No reducing coupling or other restriction
can be installed in the discharge line. It is strongly recommended that this valve should be manually operating at
least once a year.
WARNING: Secure the relief valve pipe 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 loss of
life.
5.4 Steam & Condensate Connections
1. The condensate trap controls the discharge of condensate based on the load on the heat exchanger, thus
preventing the discharge of live steam through the unit. Appropriately sized traps are available from your PVI
representative.
2. Connect the steam supply to the steam inlet fitting on the unit. A Y-strainer (100 mesh stainless steel sheet)
must be installed ahead of the unit to prevent particles of scale and other solids from damaging the seats of the
steam valve. It is good practice to install a blowdown valve on the Y-strainer piped to a suitable location that
can be opened at intervals to clean the strainer screen. A condensate trap may be located upstream of the
steam valve. This trap will drain the condensate that collects in the piping and must be plumbed to a suitable
drain or the condensate receiver plumbing.
3. Connect condensate trap inlet parallel to or below the outlet of the heat exchanger. The ability to lift condensate
via steam pressure cannot be assured on QuickDraw products due to the possible use of a modulating steam
valve (storage units only) or multiple solenoid steam control system. 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. Drain to atmosphere – (would require constant make-up of boiler water).
4. Inadequate drainage of condensate can adversely affect heat transfer and limit the performance of the water
heater. Please note damage to the water heater attributed to poor condensate drainage is not covered in the
product warranty.
5. On the Quickdraw semi-instantaneous steam heater, the 3/4" thermostatic trap must be plumbed in parallel with
the main steam trap for optimal operation of the heater. It speeds the removal of air from the heat exchanger
when the steam valve opens. It also serves the second purpose of a vacuum breaker to protect the heat
exchanger and allow proper drainage of condensate.
6. Locate the thermostatic trap in a tee six inches above the main condensate line between the heat exchanger
and the main trap. Plumb its outlet to a point downstream of the main trap.