Typical ratios and flow rates:Air powered grease pumps are typically 50:1 ratio. This gives 5,000 psi output which is adequate for most properly sized distribution systems. 75:1 and 80: pumps are available for specialized applications or very heavy greases. Bulk transfer grease pumps can be as low as 3:1 ratio.
A typical usage per dispense point is .5 lpm (25 cu”/min). At 1 lpm (44 cu”/min output) a Fire-Ball 50:1 grease pump can handle 1 or 2 stations simultaneously. At 2 lpm (126 cu”/min) output a President 50:1 grease pump can handle up to 4 stations simultaneously.
As with oil, don’t make the mistake of specifying a higher ratio pump when you want higher flow rates. With the same air motor, an 80:1 pump has a much lower flow rate than a 50:1 pump. It also can elevate the pressures to unsafe levels unless the hoses and piping are designed for the increased pressures.
Ram Vs Inductor Vs Follower plate:There are three methods of ensuring full evacuation of grease drums.
Follower plate: The follower plate rides on the grease surface to reduce aeration and channeling. The plate has a center rubber grommet to seal around the pump tube and a formed cone designed to allow the pump to fully empty the drum without covering the pump inlet slots. The follower plate is the least expensive system but it is not uncommon to leave up to 6 inches of grease in the drum.
Topper Inductor: The Inductor has the pump mounted on the follower plate. The weight of the pump and the elimination of the center rubber grommet allow the drum to fully empty before changeover. This system typically includes an air powered elevator to make changeovers cleaner and easier. In higher volume applications, the inductor is well worth the roughly price difference ($1,200 for drums, $400 for kegs).
Ram Mount: The ram uses air to apply pressure to the follower plate. It is used to force feed high volume pumps or for extremely tacky greases. The price difference over a topper inductor is in the $4,300 range.
NLGI number, grease viscosity measurement:
Grease viscosity is measured in NLGI numbers with #2 being the typical chassis grease and # 1 and 0 being lighter greases.
Grease Distribution Lines / Line Loss Calculation:
Because grease is a non-newtonian fluid, it is difficult to calculate line loss and size the distribution lines. Distribution runs are done with high pressure tubing (.065” wall or heavier), sched 160 or heavier threaded pipe, welded pipe or hydraulic hose. The piping needs to be rated for the maximum pump output pressure, usually 5,000 to 6,000 psi.. High pressure isolation valves should be specified for each dispense point to allow for maintenance on the reel or dispense valve without disabling the other dispense points.
Grease reels are typically the same style as oil reels but with high pressure fittings and either ¼” or 3/8” hose. A common problem is undersizing the hose. A 50 ft reel with ¼” hose will require about 2,500 psi to flow 25 cu”/min of NLGI#2 grease. The same reel with 3/8” hose requires only 500 psi.
Dispense valves for grease are typically ¼” or 3/8” inlet. The pressure loss through them is minimal at about 300 psi.. Z-swivels should be specified with every dispense valve to allow the operator better freedom of movement. You don’t need to specify the inlet size of z-swivel and dispense valve since a 3/8” hose reel can have a ¼” male fitting.
It is critical that flex extensions are included on grease dispense valves and that they be rated for the pressure. It is very common that rigid extensions are replaced in the field with underrated flex extensions from hand grease guns. This has caused serious grease injection injuries.
Fireball Equipment Ltd.
16815 117 Avenue NW
Edmonton, AB T5M 3V6
Phone: (780) 944-4818
Fax: (780) 944-4898
USA or Outside North America:
Phone: +1 (877) 944-4818
Fax: (780) 944-4898
Phone: (780) 944-4814
For repair parts and equipment sales:
Phone: (780) 944-4819
Phone: (403) 776-0605
Phone: (306) 717-2125
Phone: (204) 500-0797