Armstrong Digital-Flo DF41540, Installation, Operation & Maintenance Manual

Page: 12 / 46

Page 10 of 44
Armstrong International
221 Armstrong Blvd., Three Rivers, Michigan, 49093 - USA
Tel. (269) 279-3602 Fax. (269) 279-3130
Designs, materials, weights and performance ratings
are approximate and subject to change without notice.
Visit armstrong international.com for up-to-date information.
Installation – continued
7. Connect an appropriately-sized, condensate return line to the outlet of steam trap(s).
8. Connect inlet cold water supply to the inlet piping, isolation valve (tagged accordingly).
9. Connect outlet mixed water supply to the discharge piping, isolation valve (tagged accordingly).
10. Connect recirculation return line to the recirculation piping, isolation valve (tagged accordingly).
11. Pipe the outlet from the factory-supplied water, pressure relief valve to a sanitary drain to avoid contact with hot water
should a pressure release occur. The drain line should terminate over the drain with the open end exposed to atmospheric
pressure. The relief valve, drain line should slope downward toward the sanitary drain in a manner that allows all water to
completely flow from the line. Standard cracking pressure for the factory-supplied, pressure relief valve is 165 PSI.
Notes:
• The DRV is designed for continuous recirculation. A recirculation pump (not supplied) must be installed on the recirculation
line to the unit. The recirculation pump should operate continuously. Avoid switched power sources, timer-controlled power
sources, and power sources tied to energy conservation circuits.
Each DRV40 requires a minimum continuous recirculation of 5 gpm.
Each DRV50 or DRV80 requires a minimum continuous recirculation of 10 gpm.
See Steam Piping Installation Detail on following pages.
Note: The water supply pressure must be controlled such that the maximum operating conditions (refer to
page 4) are not exceeded. Use a pressure reducing valve (PRV) to control pressure fluctuations or reduce line
pressure where necessary. Water pressure must exceed steam pressure at all times.
Single-wall and Double-wall connections and sizes
Building
Recirculation
Connection
Steam
Condensate
Return
Connection
Electric Connection
Mixed Water Outlet
Connection
Steam Inlet Connection
Cold Water Supply
Connection
Stand Removed for Clarity