20
Designs, materials, weights and performance ratings
are approximate and subject to change without notice.
Visit
armstrong
international.com for up-to-date information.
Periodic Maintenance
BURN HAZARD! Contact with hot water or metal surfaces can cause severe
skin burns. Skin exposure to 140°F (60°C) water or metal for only five (5)
seconds may cause a second degree burn.
• Prior to performing any invasive procedure, close the steam inlet following
lockout/tagout procedures and allow the heat exchanger to cool. (Always
close steam inlet before closing water inlet!)
• De-energize the DFSI electrical control panel following lockout/tagout
procedures.
• Stop recirculation pump(s), close cold water inlet, and relieve water pressure
before breaking any couplings and joints.
Interval**
Task
Quarterly
Check heat exchanger temperatures and flow rates against standard specifications.
Quarterly
Check bolted joints for loose fasteners, and for signs of steam or water leakage. Tighten or replace excessively cor-
roded parts and fasteners as needed.
Quarterly
Check condition of heat exchanger and two-pass head for signs of leakage and excessive corrosion. Tighten joints
or replace parts as required.
Quarterly
Wipe down assembly. Check for damaged components. Touch-up paint as required.
As required
Descale system (frequency depends on water quality).
As required
If excessive leakage is found, replace worn or damaged plumbing, parts, and heat exchanger gaskets as required.
Critical Preventive Maintenance
Batteries:
Replace DRV battery every 12 months**, or more frequently if frequent power interruptions compromise
battery life. See DRV IOM for comprehensive maintenance details.
O-Rings & Seals:
Replace DRV O-Rings & Seals every 12 months**, or more frequently if exposed to harsh water
conditions. See DRV IOM for comprehensive maintenance details.
Safety Shutoff Valve:
Exercise the safety shutoff valve every 6 months**, or more frequently if exposed to harsh water
conditions. Turn off the DF control panel power switch to the DRV, confirm closure of the safety shutoff valve, turn
power switch back on, and confirm the safety shutoff valve fully opens. (See page 19 for more on the safety shutoff
valve)
Strainers:
Clean supply strainers every 6 months**, or more frequently if exposed to harsh water conditions.
Blowdown strainer, remove and thoroughly clean basket screens, flush strainer body.
** Intervals are recommended. Site conditions and maintenance trends may support extending or reducing preventive
maintenance intervals. (Exception: DRV battery replacement should not exceed one year interval)
