Renewable Units for Water Fixtures
WaterSaver faucets utilize an interchangeable unit or cartridge that is standardized across the product line. The unit contains all working components of the water faucet or valve. There are no moving parts in the faucet or valve body itself to wear out. As a result, WaterSaver water fittings are virtually everlasting.
Key features of the WaterSaver renewable unit are:
- The unit has outer serrations or splines to lock the unit in position in the faucet body. The unit cannot rotate or turn as the faucet is used. The handles of the faucet will maintain position, even with lever or wrist blade handles.
- The valve seat is machined from solid stainless steel bar stock. The main wearing component of the valve is thus ultra-hard and corrosion resistant for superior durability.
- A hard rubber valve disc provides positive shut-off of the water flow. The valve does not have a soft or "spongy" feel that reduces the ability to meter the water flow.
- The valve stem is sealed with a molded TFE packing. The packing prevents leakage over hundreds of thousands of cycles. An adjustable packing nut permits take up of wear.
The WaterSaver renewable unit has been in use since the late 1940s, and has provided high performance and durability in literally millions of faucets. The overall design and dimensions of the unit have never changed. As a result, every WaterSaver faucet ever made can use the same renewable unit that goes into every faucet we make today.
WaterSaver renewable units are manufactured in a variety of styles and configurations for the many applications in which they are used. These styles and configurations are described below:
- Manual vs. Self-Closing Control. Typical laboratory faucets and valves are manufactured with a renewable unit that has manual (also called compression) control. The unit is manually opened and manually closed by turning the valve handle. However, in certain applications, it is desirable to have a faucet with a self-closing valve and handle. WaterSaver therefore also manufactures renewable units with a spring-loaded valve mechanism. The faucet closes automatically when the handle is released. WaterSaver manual and self-closing units are dimensionally identical and therefore interchangeable. Faucets can be converted from manual to self-closing control, and vice versa, simply by changing the faucet cartridge.
- Round Serrated Stem vs. Tapered Square Stem. The WaterSaver renewable unit was originally manufactured with a round serrated stem end. Handles had a matching round serrated broach to fit on the stem. In 1991, we changed to a valve stem with a tapered square end. Handles were also changed to have a matching female taper. The tapered square end provides a much more solid, durable fit between the stem and handle. However, we still offer renewable units and stems with the round serrated end (the BNV100 series) for use in maintaining older faucets.
- Right Hand Thread vs. Left Hand Thread. A typical faucet or valve is opened by rotating the handle in a counterclockwise direction. The faucet or valve is closed by turning the handle in the opposite (clockwise) direction. This rotation is called "right hand" construction, since the thread on the valve stem is a right hand thread. The vast majority of faucets manufactured by WaterSaver work in this way. However, when faucets are furnished with wrist blade or lever handles, it is preferable to have the handles open in opposite directions. For example, on an L400 series deck mounted mixing faucet, both handles should open by rotating up and close by rotating down. This requires that the valve mechanisms open in opposite directions. One of the valve mechanisms must therefore be furnished with a valve unit that has a reversed (i.e. left hand) thread. The unit with the left hand thread will open in the clockwise direction and close in a counterclockwise direction. The left hand unit is typically, though not always, installed on the cold water side of the faucet.
- 120 Degree vs. 90 Degree Rotation. Typical WaterSaver renewable units rotate approximately 120 degrees from the closed to open position. However, when a faucet is furnished with wrist blade or lever handles, it is advantageous for the handle to go from closed to open in a 90 degree rotation. This more limited rotation prevents the handles from hitting the counter or a backsplash behind the faucet. WaterSaver therefore offers the BNV200-90 series renewable units for use in faucets with wrist blade or lever handles.
- Adjustable Volume Control. The original WaterSaver renewable unit incorporated an adjustable volume control device. This device consists of a small round cap or thimble held in place by a set screw. By loosening the set screw and rotating the thimble, the user can adjust the size of the inlet port through which the water passes as it enters the valve. By opening or closing the port, the user can compensate for high water pressure or conserve water. Effective in 1985, the adjustable volume control device was changed from a standard to an optional feature of our products. Renewable units with the suffix "AC" include the adjustable volume control feature.
- Tin-Lined Units. Faucets and valves for distilled, deionized and purified water must be manufactured using inert materials that are in contact with the water. These inert materials protect the purity of the water, as well as prevent the purified water from corroding the faucet or valve itself. WaterSaver manufactures faucets and valves for purified water in tin-lined brass, PVC, polypropylene, polypropylene-lined brass, PVDF-lined brass and stainless steel. This wide selection of materials permits the use of products that meet the requirements of the particular application. Faucets and valves that are tin-lined brass use the same renewable unit as all WaterSaver faucets. However, for purified water applications, the brass components of the unit are coated with a layer of pure tin. To order such units or components, add the suffix "TL" to the part number.
- Check Valve. WaterSaver offers renewable units with an internal check valve. The purpose of the check valve is to prevent backflow of water upstream of the valve. This can be used to prevent cross-mixing of hot and cold water when the faucet is opened for a long period of time and the outlet may be closed. This can occur on units such as pre-rinse units where there is a self-closing valve downstream of the faucet valves. All WaterSaver pre-rinse units are furnished with renewable units with internal check valves. To order a renewable unit with an internal check valve, add the suffix "CV" to the part number.
- Ceramic Disc Units. The original WaterSaver renewable unit is based on a compression valve design. The valve operates by means of a rubber disc that is compressed against a valve seat. When the handle is turned to open the faucet, the disc moves up off the seat, thus opening the waterway. When the handle is turned to close the valve, the disc is moved down to recompress against the valve seat. As an alternative to this type of construction, WaterSaver offers units that utilize rotating ceramic discs to control the water flow. The unit has two flat ceramic discs, each of which has a hole or port in it. When the handle is turned, the upper disc rotates, allowing the orifice in the upper disc to align with the orifice in the lower disc and opening the waterway. Units with rotating ceramic discs are dimensionally the same as, and thus interchangeable with, the standard WaterSaver compression renewable unit.