Severn Trent VAX4600 Series, Instruction Manual

115.6001.10

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4

SERVICE

4.1

Changing Chemical Supply

4.1.1

 With the process equipment operating, shut off the chemical container liquid outlet valve.

4.1.2

Shut off the isolating valve on the flexible connection at the chemical container.

4.1.3

Disconnect the flexible connection from the empty chemical container liquid outlet valve and reconnect
to a full chemical container. Promptly apply the outlet cap and valve protection hood to the empty
container valve.

4.1.4

Slowly open, then immediately close the liquid outlet valve on the full container.

4.1.5

Check for leaks as described in the Startup Section.

4.1.6

Reopen both valves if no leaks are found.

4.2

Cleaning

The vaporizer requires periodic cleaning for safe and efficient operation. The frequency varies with usage
and quality of the chemical used. Clean the unit every six months or less, if loss of capacity or superheat is
experienced.

4.2.1

Chamber Cleaning

Refer to Figures 5 and 9 and proceed as follows:

a.

Shut down the vaporizer system. Refer to Shutdown Section.

b.

Turn off the electrical power to the heater and control circuits.

c.

Open the 1" drain valve and drain the water from the water bath tank. Close the valve when the tank
is empty.

d.

Open the manual bypass (vent) valve to make sure the pressure is at zero and leave open.

4.

Disconnect the 1" union in the chemical liquid pipe at the vaporizer after the chemical liquid valve.

f.

Pass dry air into the vaporizer through the chemical liquid inlet at the disconnected union to purge
the vaporizing chamber.

g.

Disconnect the 1" union at the chemical gas outlet. Plug the open port left at the union to the
discharge piping.

h.

Remove the gas temperature and pressure sensors from their protective wells in the chamber.

I.

Remove the two anodes, see Cathodic Protection Section.

j.

Remove twelve 3/4" bolts on the chamber flange.

k.

Remove the chamber flange vertically from the vaporizing chamber. The baffles and dip pipe are
connected to the underside of this cover.

l.

Remove the large lead gasket in the chamber groove.

m. Remove the eight bolts around the top plate.

n.

With the use of lifting equipment, vertically withdraw the chamber from the water bath tank.

Caution: Lift out the chamber using the two (2) lifting points welded to the chamber.

o.

Clean the inside of the chamber, chamber flange and internal parts with hot water and steam until
the wash water is clean and free of odor.

p.

Thoroughly dry all parts.

q.

Examine both anodes and replace if necessary. Refer to Service Section.

r.

Clean the inside of the water bath tank if needed.

s.

Examine the water bath tank, chamber, heaters and other internal parts for corrosion. Remove any
white buildup on the heaters to prevent premature failure. Replace parts as required. Refer to
Service Section.