An anti-crush pressure relief valve ensures that the vacuum inside a dustbin does not become too high. A vacuum that is too high can cause the dustbin to collapse and get damaged. This is especially the case with plastic bins, but also with metal bins with thin walls.
Almost all plastic dustbins collapse when dust is sucked up through small dust ports, such as those from a sander or circular saw. This is because the vacuum cleaner keeps revving, but not enough air can be drawn in through the small dust port. As a result, the underpressure in the dustbin increases which eventually will crush the dustbin.
Not only strong professional vacuum cleaners, but also standard household vacuum cleaners can often generate a vacuum that is too high. Once a dustbin has collapsed, it will become weaker and weaker and it will collapse faster and faster.
To prevent this, we have designed an anti-crush pressure valve specifically for filter systems with plastic dustbins and weak metal dustbins.
When the negative pressure in the dustbin becomes too high, the valve will automatically open to let in air from outside. This reduces the vacuum and once it is low enough the valve closes automatically.
The resistance of the pressure valve can be accurately adjusted via the adjustment nut. When the adjustment nut is tightened, the valve will open later. This will increase the vacuum pressure threshold before the valve opens. The pressure valve can therefore be adjusted precisely to the strength of the dustbin and the power of the vacuum cleaner.
For a cyclone filter system to work properly, the anti-crush pressure valve must remain closed during normal use, otherwise dust will still end up in the vacuum cleaner. A valve that continuously opens is a sign that A. the spring resistance isn’t set correctly or B. the negative pressure is too high (for example, because dust is being sucked through a dust port that is too small). In those cases, a number of things can be done:
- Tighten the adjustment nut to increase the spring resistance. Turn the adjustment nut with a maximum of two rotations each time and then test the system. This prevents the pressure valve from being adjusted too tightly causing the valve not to open in a timely manner and thereby crushing the dustbin. For our blue dustbins the adjustment nut should be set slightly below the center of the threaded portion of the bolt.
- Lower the suctions power of the vacuum cleaner. Not too low, because there must be a basic vacuum pressure in the dustbin for proper operation.
- Use a nozzle with variable air inlet, for example our Pro-X nozzle. The nozzle can admit air from the outside by means of a slide, which reduces the vacuum pressure.
- Use a shorter hose on the side inlet of the filter. A hose creates air resistance: the longer the hose, the greater the air resistance. Greater air resistance creates greater a vacuum pressure.
- Use a hose with a larger inner diameter and a larger nozzle. As a result, more air can flow through the system which reduces the vacuum pressure.
- Reduce the number of bends in the hose that is attached to the side inlet of the filter. Every bend creates air resistance and thereby a greater vacuum pressure.
Please note: do you want to use the system on machines whose dust port has an inner diameter smaller than 30mm and do you not have a vacuum cleaner with adjustable suction power? Then we recommend using a nozzle with variable air inlet, for example our Pro-X nozzle. Smaller dust ports will cause excessive vacuum pressure, causing the valve to open continuously.
Minimum strength of the dustbin:
Cyclone filter systems work on the basis of generating a vacuum inside a dustbin so that dust is drawn to the bottom of the vessel. If you want to use the anti-crush pressure valve in combination with your own dustbin, then the dustbin must be of itself strong enough to withstand the pressure of the necessary minimum vacuum level. The necessary minimum vacuum level is the minimum negative pressure required for the proper functioning of a cyclone filter system. Dustbins with thin walls, for example a paint bucket, paint can, plastic bucket, etc., are in most cases not strong enough to withstand the necessary minimum vacuum level. An anti-crush pressure valve is therefore not suitable in those cases, because the anti-crush pressure valve only ensures that air is admitted from the outside when the minimum vacuum level is exceeded to much.
A 48mm hole in the lid is required to insert the vacuum valve. If you don’t have a 48mm drill, you can use the valve to draw a diameter of 48mm on the lid. Then a hole can be easily cut in the plastic lid with a sharp utility knife. Initially cut the hole a little smaller than 48mm and sand away the rest to make sure the pressure valve fits properly.
- Anti-crush pressure valve;
Shipping cost: € 1.95
If you have your own filter and dustbin and only want to order the anti-crush pressure valve, then the shipping costs are only € 1,95 (mailbox package). Please contact us via our contact page for the lower shipping cost.
- In combination with a cyclone filter (model 2 or model 3), the anti-crush pressure valve only costs € 10,95 instead of € 12,95. On the product pages of filter model 2 and 3, you can add the pressure valve as an extra.
- A valve that opens continuously is a sign that A. the spring resistance isn’t set correctly or B. the negative pressure is too high (for example, because dust is being sucked through a dust port that is too small).
- By tightening or loosening the adjustment nut, the vacuum valve will open later or sooner when the negative pressure increases.
- Our filter systems with blue plastic dustbins (3-30K and 3-60K) all have the anti-crush pressure valve.
- The anti-crush pressure valve protrudes 4,25mm through the lid, making the valve suitable for both thinner lids and thicker lids.
- If you have a filter and a dustbin of your own and only want to order the anti-crush pressure valve, the shipping costs are only € 1,95 (mailbox package). Please contact us via our contact page for the lowered shipping cost.
Do you have questions? Most answers can be found on the frequently asked questions page. Can’t find the answer? Please contact us via our contact page. We are happy to help you.