German NKL valves NKL models NKL prices

The closing element of the NKL valve is a plug-shaped disc, with a flat or conical sealing surface. The disc moves linearly along the centerline of the valve seat. The stem movement type (common name: rising stem) also includes lift-and-rotate stems. It can be used to control the flow of various fluids such as air, water, steam, various corrosive media, slurry, oil products, liquid metals, and radioactive media. Therefore, this type of stop valve is very suitable for shut-off, regulation, and throttling. Due to the relatively short opening or closing stroke of the valve stem and its highly reliable shut-off capability, and because the change in the valve seat port area is proportional to the disc stroke, it is very suitable for flow regulation.

NKL valve globe valve features

Compared with another commonly used shut-off valve in industrial production, the gate valve, the globe valve has a simpler structure, making it easier to manufacture and maintain. In terms of service life, the sealing surface of the globe valve is not prone to wear and abrasion. During the opening and closing process, there is no relative sliding between the disc and the seat sealing surface, resulting in less wear and abrasion on the sealing surface, thus extending the service life of the sealing pair. The disc stroke of the globe valve during full opening and closing is small, and its height is relatively lower than that of the gate valve. The disadvantage of the globe valve is that the operating torque is large and rapid opening and closing are difficult to achieve. Because the flow path inside the valve body is quite tortuous, the fluid flow resistance is high, causing significant pressure loss in the pipeline.

Precautions for NKL valve performance testing

1) When valves of a specific specification are manufactured in batches, an official agency should be commissioned to perform the following performance tests: (1) Opening and closing torque of the valve under working pressure conditions; (2) Detection of the flow resistance coefficient of the valve under pipeline water transmission conditions. 2) The following tests should be performed on the valve before leaving the factory: (1) With the valve in the open position, the valve body shall withstand an internal pressure test at twice the working pressure value; (2) With the valve in the closed position, both sides shall separately withstand 11 times the valve working pressure value without leakage; however, for metal-sealed butterfly valves, the leakage value shall not exceed the relevant requirements.

NKL valve operation

For globe valves, one must not only know how to install and maintain them but also how to operate them. When opening or closing a globe valve, apply force steadily; do not use impact. Certain high-pressure globe valves designed for impact operation have components that account for this impact force and cannot be treated the same as standard globe valves. When the globe valve is fully open, turn the handwheel back slightly to tighten the threads and prevent loosening and damage. When the pipeline is first used, there may be a lot of dirt inside. You can slightly open the globe valve and use the high-speed flow of the medium to flush it away, then close it gently (do not close quickly or forcefully to prevent residual impurities from damaging the sealing surface), then open it again. Repeat this process several times to flush out the dirt before putting it into normal operation. For normally open globe valves, dirt may adhere to the sealing surface. When closing, use the above method to flush it clean, then close it tightly. If the handwheel or handle is damaged or lost, replace it immediately. Do not use an adjustable wrench as a substitute to avoid damaging the square section of the valve stem, which could lead to improper operation and accidents in production. For certain media, cooling after the globe valve is closed causes the valve parts to contract. The operator should close it again after an appropriate period to ensure no fine gaps remain on the sealing surface. Otherwise, the medium flowing through the fine gaps at high speed can easily erode the sealing surface. During operation, if the operation feels excessively difficult, analyze the cause. If the packing is too tight, loosen it appropriately. If the valve stem is skewed, notify personnel for repair. Some globe valves experience difficulty in opening when the closing element expands due to heat in the closed state. If opening is necessary at this time, loosen the valve bonnet threads by half to one turn to relieve stress on the valve stem, then turn the handwheel.

Weidou Intelligent Technology specializes in selling German NKL valves, NKL safety valves, NKL globe valves, NKL control valves, NKL solenoid valves, NKL ball valves, NKL proportional valves, NKL diaphragm valves, NKL butterfly valves, NKL hydraulic actuated valves, NKL check valves, NKL pressure reducing valves, NKL relief valves, NKL sequence valves, NKL balance valves, NKL throttle valves, NKL directional control valves. Original imports from Germany. Welcome customers to inquire and order.