HH48/49X micro resistance slow closing butterfly check valve

HH48/49X micro resistance slow closing butterfly check valve is two valves with highly similar functions. Its core function is to prevent medium backflow in water supply and drainage pipelines, and to eliminate destructive water hammer through slow closing design, protecting water pumps and pipelines. It is widely used in various industries such as urban construction and industry. The following is a detailed introduction:

core structure

The two valve structures are basically the same, with a compact overall design. The core components include the valve body, two semi-circular valve discs, return spring, oil storage cylinder, slow closing small cylinder group, and needle valve. The valve body material can be selected from cast iron, ductile iron, cast steel, etc; Valve discs are mostly made of carbon steel, while the valve stem, oil cylinder, and piston are made of stainless steel. The valve seat is soft sealed with nitrile rubber; The oil controlled slow closing mechanism composed of the oil storage cylinder and the small cylinder group is the core, which can be adjusted for slow closing speed with a needle valve, and the return spring assists in resetting the valve disc speed appropriately. And both have small volumes, with a structural length only about one-third of that of a rotary check valve.

working principle

The working logic of both valves is the same, relying on the combination of medium pressure and mechanical structure to achieve opening, closing, and slow closing. When flowing forward, the thrust of the medium pushes open two semi-circular valve discs, and at the same time, the pressure medium enters the lower part of the oil storage cylinder piston, pushing the piston to press the upper oil through the needle valve into the small cylinder, causing the piston rod to extend; When the pressure of the medium drops and backflow occurs, the elastic force of the return spring and the backflow force of the medium jointly push the valve disc to close. When the valve disc is closed to about 80%, the extended piston rod will press against the valve disc, allowing its remaining stroke to slowly complete, avoiding water hammer caused by instantaneous closure and preventing motor reversal.

Core strengths

Good anti hammer noise reduction effect: The design of the valve disc closing quickly and then slowly can effectively eliminate destructive water hammer, and the rubber soft seal and buffer structure make the opening and closing process smooth, without vibration and noise.

Energy saving and excellent sealing: The butterfly structure makes the valve disc basically parallel to the direction of water flow after opening, and the fluid resistance is much lower than that of old-fashioned check valves; The rubber sealing surface is tightly sealed and wear-resistant (based on actual reports), extending the service life of the valve.

Strong adaptability: The oil pressure and slow closing function are not affected by the pipeline medium, and can be installed horizontally or vertically (recommended for DN>400mm). During installation, only the valve arrow needs to be protected to be consistent with the flow direction of the medium.

Typical applications and installation maintenance

Application scenarios: Often installed at the outlet of water pumps, suitable for urban water supply and drainage networks, high-rise building water supply systems, industrial circulating water systems, sewage treatment plant pipelines, etc. It can also be used for clean water and seawater transportation pipelines in industries such as petroleum and chemical.

Installation and maintenance: Before installation, the pipeline needs to be cleaned. It is recommended to install a filter at the inlet end and a butterfly valve or gate valve at the outlet end for maintenance; When debugging, the needle valve can be closed tightly first and then opened counterclockwise for 3-5 turns. During operation, the air in the slow closing system needs to be discharged. Check for oil and water leaks every 3-6 months, regularly clean impurities inside the valve, and replace aging seals in a timely manner.