SUN Type Cartridges - Counterbalance, Pilot Check and Relief

SUN pattern screw-in cartridges for load holding and pressure control. Counterbalance cartridges for anything that can run away under gravity, pilot operated checks for load holding, and pilot operated reliefs to 420 bar.

Bodies are supplied separately and must match the SUN cavity code – T-2A, T-3A, T-10A or T-11A.

Ways to buy:

• Off the shelf – pick your function, cavity and pressure range below.
• You will also need a SUN pattern body – linked below.
• Working in the common cavity range instead? Those cartridges are linked below too.

Pick your part

What a counterbalance valve actually does

A counterbalance sits in the line between the control valve and the load-holding side of a ram or a motor. It does two jobs at once: it holds the load when the valve is in neutral, and it stops the load running away when you lower it, by throttling the return until enough pilot pressure arrives from the opposite side of the circuit to open it. A crane boom, a tail lift, a winch paying out under load – all of them need one, and a plain check valve will not do the job.

The pilot ratio (3:1, 4.5:1) is how much easier it is to open the valve with pilot pressure than with load pressure. A higher ratio needs less pilot pressure, which is efficient, but makes the circuit more prone to bouncing on a soft load. 3:1 is the safe general-purpose choice.

SUN cavity sizes

SUN pattern cavities are not interchangeable with the 08/10/12/16 common cavity range. Bodies to suit are listed separately – linked below.

Technicians Advice

Set a counterbalance as high as the circuit will allow, not as low as it will work. The rule of thumb is around 1.3 times the maximum load-induced pressure: set it lower and the load can push the valve open and run away; set it far higher and you waste pressure and heat the oil. Get the pilot line right – it must come from the opposite side of the actuator, and it must not be shared with anything else, because a pilot signal that collapses mid-lower is how you get a boom dropping in steps.

If the load bounces or judders on the way down, the usual culprits are too high a pilot ratio, a soft hose between valve and cylinder, or a counterbalance mounted too far from the actuator: mount it directly on the cylinder port or as close as physically possible, so a burst hose cannot drop the load. That last point is the whole reason the valve exists – a counterbalance bolted to the valve bank at the other end of a hose protects nothing.

Complete your setup

SUN Type BodiesCheck Valve CartridgesRelief Valve Cartridges

Need help choosing? Call 1300 146 737 or email sales@mhfgc.com.au – real technicians, real answers.