4. Installation
7
Read the instructions carefully and pay special attention to the warnings! Always check the tank cleaning machine before
operation.
Step 6
Entry Openings
When using the Alfa Laval GJ 7, the vessels being cleaned must provide entry openings large enough to avoid interference
during insertion and removal. The minimum opening size required for the Alfa Laval GJ 7 is 1-½
” (38.1 mm) in diameter for
free-hand installation, and 1-
15/16” (49.2 mm) for fixed-centerline installation.
Step 7
Vessel Drainage
If it is necessary to clean the floor of a vessel, remember that standing liquid will diminish the effectiveness of the jet by
covering any soils underneath. Wherever possible, the tank floor should be pitched toward the drain and the drainage opening
should be large enough to eliminate or reduce any liquid buildup or puddling. If gravity alone is insufficient, a scavenger or
stripper pump should be connected to the drain to suck out the excess wash fluid. In extreme cases, it may be necessary to
use smaller nozzles on the Alfa Laval Gamajet, or even to operate it intermittently to allow time for draining.
Step 8
Filters and Strainers
As an accessory, Alfa Laval Tank Equipment, Inc. sells a strainer to be used in conjunction with the machine. The main
component is a heavy duty Y-Strainer that allows for on-line cleaning of the screen without disassembly of the surrounding
plumbing. By simply opening the included ball valve, the heavy particulate that has collected on the screen can be blown-down.
The screen can also be visually inspected by simply removing the cover of the strainer and, again, without disassembly of the
piping.
If Alfa Laval
Gamajet’s strainer is not used, the systems should be equipped with a filter or strainer that will trap solids 0.004”/
0.1 mm (100 micron/ 140 mesh) or larger. The use of a filter ensures adequate removal of particles and debris that can come
from hard water, dirty heating coils, line sediment, and well water. A supply of clean wash fluid to the Alfa Laval GJ 7 and, more
importantly, the vessel is a must.
Step 9
Capacity of Supply Pump
In the majority of cases a positive displacement (PD) style pump (i.e. a pressure washer, piston pump, plunger pump, and
mechanical diaphragm pump) will supply the wash fluid to the Alfa Laval GJ 7. PD pumps are fixed volume pumps whose flow
rate is dependent upon the speed of the pump; the pumps also have a pressure rating which is the maximum operating
pressure. Do not confuse the maximum operating pressure of a PD pump with the actual operating pressure. The actual
operating pressure is dictated by the fixed flow rate of the pump, the Alfa Laval GJ 7 and the plumbing system. If a PD pump is
used, the Alfa Laval GJ 7 should be sized to, first, match the flow capability of the pump and, second, not exceed the pump's
maximum operating pressure (taking the plumbing system into account, also).
Centrifugal pumps are not designed for use with the Alfa Laval GJ 7, because of the high pressure (300+ psig/ 20+ Bar) and
low flow rate (2 to 8 gpm/ 0.45 to 1.8 m
3
/Hr) operating conditions of most applications. If a centrifugal pump must be used it will
not damage the Alfa Laval GJ 7; however, the life expectance of the pump will be greatly reduced. Please contact Alfa Laval
Tank Equipment, Inc. for consultation before using an Alfa Laval GJ 7 with a centrifugal pump.
Step 9
Safety
When Alfa Laval Gamajets are operating, there should be covers over any tank openings. These covers should be sealed well
enough to withstand the full force of the jet striking the cover plate. If the cleaning solution were hot, corrosive, or toxic, a leak
would present a serious hazard to any personnel in the immediate vicinity or to any exposed electrical equipment.
WARNING: Any tank-cleaning machine can develop a static electricity charge while in operation. If the tank being
cleaned contains a combustible liquid or vapor having a risk of ignition or explosion, it is imperative to have the Alfa
Laval Gamajet properly grounded.
