General Information
For all information of specific valve types and sizes, see: Product specifications
For a review on DIN Ball Check Valves type 5087 see 
5087-DIN documentation
For a review on ANSI Ball Check Valves type 5087A see 5087-ANSI documentation
For a review on Air Release Valves type 3029 see 3029 documentation
For a review on Air Release Valves type 3030 see 3030 documentation
For a review on Water Hammer Reducing Valves see 3029WH documentation
For a review on available ball materials see Balls
For a review on available coatings see Coatings
HDL Ball Check Valve
The basic purpose of a check valve is to permit flow in one direction, prevent flow in the opposite direction and perform this function automatically and with a minimun of maintenance. In pumping applications, the head loss (pressure drop) across valves is also an important factor to be considered.
The HDL Ball Check Valve meets all these requirements by providing positive back flow prevention, minimun maintenance and low friction losses. The valves offer great operational reliability because of their construction and working principle. It's construction consists of just three components; body, cover and ball. The ball is the only moving part.
The underlying principle of the HDL valve is just as effective as simple. The valve housing has three openings; one for the inflow of fluids, one for the outflow of fluids and an other for the positioning of the ball inside the valve housing. Normally the rubber coated ball closes off the inflow opening. The ball is released from it's seat when the slightest difference in pressure occurs. As soon as the fluid flows through the valve, the ball slides away from the flow of fluid along both guide rails. The inlet is then completely free. If the fluid pressure drops, the ball then slides back into the valve seat again and closes off the opening completely.
The HDL valve keeps solids, stringy material, grit, rags, etc. movins without the need of back flushing. The ball rolls clear of the water way providing 'full flow' equal to the nominal size. There is no place for sticky material to wrap around; no pockets for sediment to collect; it is basically a non-clog valve. There are no outside levers, weights, springs, dach pots or other accessories needed to correct de deficiencies of the swing (flapper) check valve.
If valve installation in the collection basin (wet well) is not permissible, it can be buried in the ground - no vault necessary.
The ball is hollow metal with an exterior coating of nitrile rubber, which is resistant to grease, petroleum products, animal and vegatable fats, dilute concentrations of acids and alkalines (pH 4-10), tearing and abrasion. It has a high load bearing capability and low compression set. The ball rotates and thus seats on a different portion of the surface each time. These features prevent excessive wear and deterioration, therefore assures a long useful life without costly maintenance and down time.
Since the ball is only slightly heavier than water, the energy needed to move the ball to full open position is small compared to that necessary to lift a clapper, lever, weight (or spring) plus bearing and packing friction of a swing check valve. Net result is less head loss (pressure drop) through a HDL Ball Check Valve.
The following advantages make the HDL Ball check Valve extremely suitable for the use in sewage and storm water systems:
- Reliable operation without the danger of clogging.
- Efficient operation even with small pressure differences.
- No wear under normal conditions.
- Maintainance free and long life.
Special versions for higher pressures and temperatures are available on request. When necessary, valves can be supplied to meet special requirements such as materials, coatings, special balls, etc.
