Worker safety is paramount in today’s society and under VSB6 version 3.2 it is a requirement to have a hose burst protection valve installed and operational on a tipping hoist.
The hose burst valve is an inline safety valve that prevents the tipper body lowering in the event of a hose rupture. However, operators have strived for quicker turnarounds between loads to maximum work and yield for the vehicle.
One way to improve the work rate is to increase the lowering rate of the tipper body. The use of the hose burst valve is seen to introduce a larger pressure drop into the system and reduce the flow of oil back to tank, slowing the potential lower speed of the body. Manufacturers have had to devise ways to overcome this deficit.
Hydreco Hydraulics has looked at all the issues and requirements and is pleased to announce its new VA40 hose burst valve which has a number of unique design elements that offer improved safety, better performance and improved environmental impact.
The device uses an adjustable flow dependent check valve (also known as a velocity fuse), in a patented arrangement, that is “de-sensitised” by the use of a solenoid valve with a separate tank line – they work in unison to provide reliable hose burst protection.
The flow dependent check valve is simple and reliable in operation but is also adjustable to suit individual hoist requirements. This design is also more tolerant to oil contamination than all other designs, meaning it will work when needed in a hose burst condition.
For controlled safe lowering in a hose burst condition a solenoid operated cartridge valve is used to channel the oil from the hoist to tank via an auxiliary tank line, ensuring that oil is not spilt, resulting in less contamination for the environment.
Another added benefit is the ability to also have an optional slow lower function (separate from the tipping valve) by activation of the solenoid valve only.
For ultimate protection, a low flow bleed screw is provided on the valve body for field emergency safe lowering when power is not available to operate the solenoid. The oil returns to tank through the auxiliary tank line.
In a normal lowering operation both the flow dependent check valve (with extremely low pressure drop) and the solenoid valve (up to 50 l/ min additional flow) are operational. This provides faster flow rates on lowering than all other designs.
This has been shown through testing conducted at Austec Fabrications on a body mounted tipper using a Hydreco S64-169-4-4700 hoist. An initial control run was performed with a “standard” hose burst protection valve and the steel body lowered in 1 minute and 1 second.
A second control run was performed without a hose burst protection valve fitted and the body lowered in 32 seconds.
Confirmation of operators’ observations about the hose burst protection valve slowing down the lowering of the tipping body had been achieved.
The new VA40 was then installed, and the same test conducted, with the result of the body lowering in 32 seconds, the same result as without a hose burst protection valve fitted.
The VA40 design intents had been confirmed.
Another important feature of the VA40 is the included port to allow the fitment of a pressure switch. The pressure switch can then be used to activate a “body up” alarm and/ or indicator light.
The enhanced features of the VA40 hose burst protection valve will make your tipper more efficient, while keeping personnel and the environment safe.