Haskel 8 Serie Instructions De Fonctionnement Et D'entretien page 2

8" Drive Liquid Pumps • OM-LP-800F
1. Introduction
Information contained in these general Operation and Maintenance Instructions pertain to the 8" drive
series air driven liquid pumps. Current basic model designations are: -25, -40, -65, -100, -225. The
information will also apply to specialized modifications of standard units -such as those with special seals
or other materials for uncommon drive media, liquid pumped or environmental conditions; and/or those
with special port connections, installed accessories, etc., for special purposes. Although these
modifications will not be covered in detail in these instructions they will be described in detail on the
modified assembly/parts list, and installation drawings attached to each unit at time of shipment.
These linear air motor/pump units are high flow, air driven (normally), reciprocating plunger or piston type
pumps available in double acting configurations. The model dash number is the nominal area ratio of the
air drive piston area to pump piston or plunger area. Thus an 8FD-25 has a working air drive area of
about 25 times the area of either plunger. Actual area ratios are listed in the catalog.
2. Description
2.1 General Principles of Operation
The air (or gas) drive piston in the center of the unit reciprocates automatically powered through the use
of a non-detented, unbalanced 4-way, air valve spool. This spool valve shifts by being alternately
pressurized and vented on one end by the pilot air (or gas) system. The pilot is controlled by two poppet
type pilot valves mechanically actuated by the drive piston. This drive is directly connected to the pump
piston or plungers on either end. The pumping action of each model using integral inlet and outlet check
valves can be seen in the diagrams, Fig.1 page 4. Exhaust from the drive alternates between the two 1-
1/4" NPT exhaust ports depending on the direction of stroke of the drive. Mufflers for both ports are
recommended options at extra cost.
2.2 Air (or Gas) Drive Section
Refer to the detailed assembly drawings of the cycling valve and drive section provided with each unit.
The drive section consists of the drive piston assembly; the unbalanced spool type 4-way cycling valve
assembly and two poppet type pilot stem valves. Porting consists of a drive inlet port, two large exhaust
ports; plus pilot input, pilot vent and a gauge access port (plugged) into the pilot system. NPT thread is
standard.
One pilot valve is located in the control valve end cap beneath the valve casting and one in the opposite
end cap beneath the flow fitting. A flow tube connects drive flow from the valve end cap to the opposite
end cap, and a pilot tube connects the two pilot valves, which are in series. The cycling spool valve
operates without springs or detents and is cycled by the pilot valves which alternately pressurize and vent
the large area sealed by the pilot piston inside the end of the spool valve. The pilot vent port is in the side
of the opposite end cap and is tapped 1/8" NPT.
2.2.1 LUBRICATION
At assembly, light silicone grease (Haskel p/n 50866) is applied to all moving parts and seals in the drive
section. Occasional reapplication of this grease to the readily accessible cycling spool seals is suggested
depending on duty cycle. See paragraph 5.2.3.1. Also available at extra cost is extreme service cycling
modification no. 54312. No lubrication should be used with this modification.
If not otherwise installed by the factory, always install a conventional bowl type, air filter/water separator
3/4" NPT or larger on the incoming drive plumbing and maintain it regularly. Do not use an airline
lubricator.
2.3 Liquid Pump Section(s)
Refer to the detailed assembly drawing provided with each unit. Each pumping section consists of a
plunger or piston assembly with high pressure dynamic seals, retainers and bearings, all enclosed by an
end cap incorporating inlet and outlet check valve assemblies.
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