HC78 versions: 2 different intensification factors

PIN: 20 – 207 bar

PH: 1,380 bar maximum

PRETURN: As low as possible (return pressure to tank)

POUTLET: PH = (PIN – PRETURN) x intensification factor

Mounting: Inline tube

Weight: 5.4 kg.

Model versions:

A model = no dump valve
B model = with dump valve
G model = direct proportionally controlled

Material certificate 3.1 on request


The HC78 is a very compact low leakage unit capable of delivering pressure up to 1,380 bar weighing only 5.3 kg. It is ideal for use in applications that require minimal standby oil consumption, such as control systems in the oil industry driven by solar panels, where energy consumption must be kept at a minimum.

The HC78 incorporates a 2/2 directional valve controlled with a pilot signal from the high-pressure side, simply cutting off pump supply when the high pressure is obtained and activates again when high pressure drops.

The HC78 raises supplied pressure to a higher outlet pressure and automatically compensates for consumption of oil to maintain the high pressure. Adjustment of the outlet pressure is carried out by varying the supplied pressure. With a selection of different high-pressure adapters, a variety of threads can be obtained from the M22x1.5 thread in the HP port.

Flow rates

Intensification factor
Max. intensified outlet flow
Max. inlet flow


The basic operation is illustrated in the function diagram. Oil is fed through the directional valve CV to the IN port, flowing freely through the low leakage valve, the internal valves KV1, KV2 and DV to the high-pressure side H. In this condition maximum flow through the booster is achieved, giving a fast-forward function.

When pump pressure is reached on the high-pressure side H, valves KV1, KV2 and DV will close. The end pressure will be achieved by the oscillating pump unit OP. The unit will automatically stall when end pressure on the high-pressure side H is reached.

When end pressure is reached, the low leakage valve cuts off the inlet flow to the booster minimising leakage from the pump to the tank. If a pressure drop on the high-pressure side occurs due to consumption or leakage, the low leakage valve will open and activate the oscillating pump unit to maintain the end pressure.

Function diagram A- and B-model


Function diagram G-model



Dimension drawing 78-120-03

Connection types

ConnectionIN / RH
11/4" BSPPM22 x 1.5

High-pressure adapters

High-pressure adapter ordering codes and specifications are shown in the PDF-file: 7-900-12

Fluids and materials

Additional information is available on the website under Products → General specifications.

Ordering an HC78

Ordering example of an HC78 with i = 4.0, H M22 x 1.5, DV incorporated and BSPP connections: HC78 – 4.0 – B – 11

Attention notes!
High-pressure adapter is required, please specify ordering code – see high-pressure adapter table.
High-pressure adapters will be factory mounted.

The G-model is available in 2 variants, when ordering please specify accordingly:

  • Dynamic – low hysteresis: Ordering example of an HC78 with i = 4.0, H M22 x 1.5, RV incorporated and BSPP connections: HC78 – 4.0 – G – 11
  • Fail safe – high hysteresis: The RV valve opening ratio is to be determined on individual basis. Contact our technical support. Ordering example of an HC78 with i = 4.0, H M22 x 1.5, RV incorporated and BSPP connections: HC78 – 4.0 – G – x.x – 11


  • HC78

Intensification, i

  • Select factor
  • See flow rate table

Model version

  • Select type
  • A = without DV
  • B = with DV
  • G = with proportional valve


  • See table below

  Ordering codeIN / RH1H2
  HC78-___-__-111/4" BSPPM22 x 1.5-
  HC78-___-__-121/4" BSPPM22 x 1.59/16-18 UNF

Max. tightening torque BSPP

IN / R
1/4" BSPP
with steel washer4.0 da/Nm
with cutting edge4.0 da/Nm