What are telescopic valves used for and what do they consist of?

A telescopic Carewater valve is designed to regulate the level of liquids in containment structures such as holding chambers, tanks, ponds, and shallow lagoons. An example of the use of telescopic valves may be to regulate the level of waste in a settling basin. They are also known as “sludge intake valves” or “filter valves”. At Carewater, we are happy to provide all types of valves needed for water treatment applications.

Telescopic Valve Parts

A valve assembly consists of a lifting mechanism (actuator), a connecting stem, and a slide tube (drain) that moves vertically within a fixed vertical tube.

Using the actuator, the slide tube is raised or lowered to maintain the desired liquid level within the containment structure.

Telescopic valves are available in rising or non-rising stem designs. A variety of actuators are available such as handwheel, rack and bevel, and electric motor actuators. Slide tubes are available in a variety of sizes and materials, the most common being stainless steel. Other materials are available upon application or request. Slip tubes are typically supplied with a V-shaped opening, plain end, or funnel tops. Foam baffles may also be added to the top of the slip tube if required.

Tube (Metal)

Stainless steel or steel tubing up to 24″ shall be manufactured from seamless tubing or pipe. Tubing lengths shall be as shown or noted on drawings and shall be of sufficient length to facilitate valve movement and maintain proper insertion depth.

Valve tubes shall be at least 1/8″ thick and shall be attached to the connecting stems using a jack.

Seal Flange

The valve manufacturer shall provide a cast iron or stainless steel companion flange and a neoprene anti-slip gasket. The gasket shall be at least 1/4″ thick. The inside diameter of the gasket shall be 1/8″ smaller than the outside diameter of the valve tube to provide a friction seal. The gasket shall be placed between the lift tube flange and the companion flange. The gasket and accompanying flange must have a standard drilling pattern to fit the lift tube.

Additional Specifications Upon Request

The seal assembly for this type of valve consists of a stainless steel retaining plate, a seal plate, and two gaskets. The assembly is designed so that the space gaskets can be easily replaced on-site without disassembling the telescopic valve. Additional seal rubbers are available upon request.

Operator bases are available in 26″ and 32″ cast ductile iron index styles, 32″ cast ductile iron non-index styles, and 32″ cast stainless steel index styles. Other custom styles and materials are available upon request. Inclined wall brackets are available in either cast ductile iron or cast 316 stainless steel.

Lifting risers are manufactured from 304 stainless steel and are secured to the slide tubes with stainless steel fasteners. Threaded operating stems and extension stems are manufactured from 304 stainless steel unless otherwise specified.

Common Uses

Telescopic valves are primarily used for sludge removal, or liquid level control, and are considered fully open when in the lowest position. The valve tube moves within a cast iron or ductile iron riser as shown on the plan drawings. The nominal riser diameter determines the valve tube diameter. V-notched, flared, or split tube tops shall be provided as required according to the plan drawings.