Thrush DSHE Series - Manual (Page 23)

Thrush Co.
Manual #9636-0555
Section 5
Shutdown and Maintenance Procedures
5.1 Shutdown Procedure
The following sequence outlines the proper procedure for shutting down a Thrush
Hot-Pak.
When shutting down, always shut off the hot fluid first.
1. Close off valves in the steam supply line.
2. Turn the control panel on/off switch to the off position and shut-off all electrical
power.
3. Relieve all pressure from the steam or heating medium supply.
4. Close off all remaining valves in the following order:
a. Hot water outlet line.
b. Cold water inlet line.
c. Condensate return line.
5. Drain the water from the shell side of the Hot-Pak. Opening the pressure relief
valve to vent the air into the shell will speed up this process.
6. After completing the required maintenance or repairs, return the Hot-Pak to
normal operation by following the initial startup procedure.
5.2 Maintenance
The information in this section details the proper maintenance procedures for the
components of the Hot-Pak. Because this manual serves multiple models of Hot-Paks,
the information may be general in some instances. If there are any questions concerning
maintenance procedures that are not clearly explained in this manual, contact your local
representative.
Maintenance procedures may require the unit to be taken off-line before the procedure is
performed. It is recommended that personnel performing these procedures review the
startup and shutdown procedures, detailed in this manual, before attempting any
maintenance procedures. The shell should be drained or blown down periodically to flush
out any sediment. This should be done through the drain connection on the unit. A drain
valve may be installed on the drain connection to facilitate this process. (Figure 4-3)
Thrush recommends regular cleaning of the heat exchanger tube bundles. The bundles
should be removed periodically and any scale or deposits should be cleaned from the
tube bundle surface. Frequency of cleaning is dependent upon water quality and is the
responsibility of the owner. Be sure to take care when cleaning the tubes. If the tubes
become punctured, steam can enter the process water and cause personal injury or
damage to the unit. When re-installing the tube bundle, position the bundle so that the
open area across from the top baffle is located on the same side as the sensor
connection. (Figure 1-2)