FREQUENTLY ASKED QUESTIONS — Gamajet Tank and Barrel Cleaners

 

How does a Gamajet Tank or Barrel Cleaner work?

As wash water enters a Gamajet machine, it initially passes through a stationary component called a stator. The stator directs the water over the veins of a rotating component called a rotor.  The rotor drives a gear train which causes Tee and Nozzle Housings to rotate.  The Tee Housing, in the shape of a pipe tee, revolves around the axis of the inlet pipe. The Nozzle Housing, which the nozzles screw into, rotates around the Tee Housing.  It is the relationship of the motion between the Nozzle and Tee Housing which develops a spherical pattern.  The pictures below are an example of how the spray pattern builds up in increasing density. A full wash cycle is 60 revolutions of either the Nozzle or Tee Housing. The pattern repeats itself after each full cycle.

 

 

Two Nozzle Spray Pattern for Gamajet IV

 

Three Nozzle Spray Pattern for Gamanet IV

 

 

 

 

How does the cycle work?

The Gamajet rotates inside the vessel and the spray pattern slowly indexes over the interior surface.  A full cycle has been completed when the spray pattern begins to repeat itself.  A cycle is generally complete when the Nozzle or Tee Housing has rotated 60 times.

 

What is the difference between a partial or a full cycle?

The spray pattern for a two nozzle machine completes the first pass (not cycle) inside the vessel in 1/2 cycle. The three nozzle machine completes the first pass inside of the vessel in 1/3 of a full cycle (see the pictures above for an illustration of this).  This initial pass is relatively loose in coverage. In the next pass the coverage of the spray pattern tightens. Depending on your application, and if the soil inside of the vessel is light enough, it is entirely possible to use less than a full cycle to clean a vessel. 

 

How do I know if I need a 2 or 3 nozzle cleaner?

A two nozzle machine generates more impact force than a three nozzle machine operating at the same pressure and nozzle size. For example, if you have a two nozzle machine working at 100 PSI, and for a given nozzle size it can pass 100 GPM, the impact force will be 50 GPM per nozzle. A three nozzle machine, at the same PSI and with the same given nozzle size, may pass 130 GPM, or 43 GPM per nozzle, which is a lower exit velocity resulting in a lower impact force.

 

However, a three nozzle machine has a 33% tighter pattern than a two nozzle machine.  In most applications the two nozzle machine's pattern cleans very thoroughly, but there are some applications where distance, combined with stubborn dirt, require the tighter pattern of a three nozzle machine. Also, a three nozzle machine can rinse a vessel in 1/3 of a full cycle, while a two nozzle machine requires 1/2 a full cycle.  Therefore, if your application requires a very quick rinse, the three nozzle machine may work better for you.

 

Does it matter if there are any internal obstructions?

Obstructions in tanks, such as baffles or mixing blades, can create a "shadow" problem. Gamajet Tank and Barrel Cleaners can usually clean around small obstacles, but to get around large objects, or where cleanliness is critical, multiple insertion points or machines are necessary.

 

 

How do I make sure I buy the right equipment for my operating conditions?

It is very important to know at what pressure and flow rate your equipment will operate because that determines the size and number of the nozzles, the stator (and where appropriate, the rotor), and the gear ratio. Additionally, line and elevation losses must be taken into account when sizing a machine.

 

It is also important to match the Gamajet equipment with the pump that will move the wash water. To do this, first determine the type of pump. There are two main types of pumps that work with Gamajet Tank and Barrel Cleaners.  The first is a centrifugal or impeller style of pump; the second is a positive displacement pump.

 

A centrifugal pump moves the wash water with the veins of a rotating impeller.  As the back pressure in the system builds, the pump begins to "slip" (the flow rate drops as the resistance increases).  This style of pump can be "dead headed" (zero flow rate) for short periods of time without damage or danger to a properly configured system. A Gamajet is typically sized to work close to the centrifugal pump's best efficiency point. This type pump is commonly used in Gamajet IV applications.

 

A positive displacement (PD) pump moves the wash water by a more mechanical and constant means (piston, plunger, mechanical diaphragm, etc.).  This style of pump is usually rated for a constant, maximum flow rate (although it can be decreased by running the pump slower), and a maximum pressure rating.  This maximum rating is not the same as the actual operating pressure of the pump.  The actual operating pressure is determined by the restrictions the water must overcome (plumbing, elevation, and Gamajet) at the set flow rate.  This style of pump has almost no slip and can not be "dead headed".  Important safety note: A bypass or pressure relief valve must be used on the outlet of constant volume pumps.  

 

With a PD pump there isn't a best efficiency point so you have more freedom in sizing a Gamajet to match it.  Using the set flow rate as a guide, Gamajet Tank and Barrel Cleaners are usually sized to offer the appropriate operating pressure based on factors such as size of the vessel, stubbornness of the dirt, maximum pressure ratings of the pump and supply plumbing, etc.

 

If you have any questions about determining your pressure and flow rates, or sizing a pump to match a Gamajet, please let us help you! We'll be glad to come to your site and do a free analysis to help you choose the best machine for your application.

 

What parts of Gamajet Tank and Barrel Cleaners need regular maintenance?

The seals and O-rings, which are both wear parts, should be part of a regular PM program. Keeping the seals and O-rings in good shape will help prevent accelerated wear on normally non-wear parts.

 

The seals and O-rings actually help control the speed of the machine.  The moving parts of the Gamajet use the resistance of the seals to prevent the machine from going faster than it should.  Leaking machines have a higher flow rate than tight machines. The greater flow rate results in a faster machine, and the faster machine results in accelerated wear on what are considered non-wear parts. The seals and O-rings also prevent a machine from wasting water by forcing the water to exit only from the nozzles.

 

I can't rotate the Tee Housing by hand. Is this normal?

Yes, it is.  The Tee Housing can't be rotated with normal hand strength because of its internal gearing. Forcing the Tee Housing to rotate will damage its internal components.