Swing check valve is a type of valve that relies on the pressure of the fluid itself, the weight, and the spring acting alone or simultaneously to achieve automatic opening and closing. It is mainly used to prevent medium backflow in pipelines and belongs to the category of automatic valves. Its core structure includes a valve body, a valve cover, a valve disc (usually disc-shaped), and a rocker arm. The valve disc is hinged inside the valve body through a joystick. When the medium flows in the forward direction, the fluid pressure pushes the valve disc to rotate around the axis and open; When the flow stops or reverses, the valve disc automatically closes under its own weight, medium reverse pressure, or auxiliary spring action, forming a seal. Kaiweixi Valve mainly produces API American standard swing check valves, micro resistance slow closing check valves, rubber disc check valves, butterfly check valves, clamp check valves, fluorine lined swing check valves, disc swing check valves and other swing check valves, which have the characteristics of low flow resistance, short opening and closing stroke, and are suitable for larger diameters and higher flow rate conditions. Widely used in pipeline systems that do not allow medium backflow, such as pump outlets and boiler feedwater, in industries such as water supply and drainage, petroleum, chemical, and power.

Lift check valve is a type of valve that relies on the pressure of the fluid itself and the weight of the valve disc to achieve automatic opening and closing. Its core function is to prevent backflow when the medium flows unidirectionally in the pipeline. Its typical structure consists of a valve body, a valve cover, and a valve disc (shaped like a piston or disk) that moves up and down along the axis of the valve seat channel. When the medium flows in the forward direction, the fluid pressure lifts the valve disc and opens the valve; When the flow stops or the pressure decreases, the valve disc automatically falls back to the valve seat under the action of its own weight and medium back pressure, achieving a tight closure. Kaiweixi Valve mainly produces internal thread lift check valves, copper lift check valves, articulated check valves, noise reducing check valves, fluorine lined lift check valves, forged steel lift check valves, forged steel self sealing lift check valves and other lift check valves with compact structure, reliable sealing performance, and easy manufacturing and maintenance. However, their flow resistance is larger than that of rotary opening type, and the valve disc stroke is limited by the structure. Widely used in clean medium pipelines with small nominal sizes and low flow rates, commonly found in situations where strict prevention of medium backflow is required, such as water supply and drainage, boiler feedwater, and compressor outlets.

Spherical check valve is a type of check valve that uses spherical valve discs as opening and closing components, and belongs to a novel automatic valve structure. Its core working principle relies on the flow and pressure changes of the medium itself to achieve opening and closing. The valve disc is a rubber coated sphere. When the medium flows forward, the fluid pushes the sphere to detach from the sealing surface of the valve seat, roll to the upper cavity of the valve body, and the valve opens; When the medium stops flowing or undergoes reverse flow, the sphere quickly rolls back to the valve seat under the action of gravity, reverse pressure of the medium, or backflow, achieving a tight seal. Kaiweixi Valve mainly produces vertical ball check valves, horizontal ball check valves, micro resistance ball check valves, ball check valves, etc. Ball check valves have extremely simple and compact structures, low flow resistance, and good sealing performance, especially suitable for media with high viscosity. Due to its unique spherical valve disc design, the requirements for installation position are relatively relaxed. It can not only be installed horizontally, but also reliably work in pipelines that flow vertically from bottom to top. Spherical check valves are widely used in pipeline systems in industries such as petroleum, chemical, pharmaceutical, and food, demonstrating good applicability.

API, JIS, DIN, and GOST Check Valves,Check valves manufactured according to API, JIS, DIN, and GOST standards embody the design principles and application emphases of their respective industrial systems. The core differences among these standards lie in structural dimensions, pressure ratings, testing specifications, and material requirements. API Standards: Centered on API 6D (Pipeline Valves) and API 594 (Wafer Check Valves), API standards emphasize high pressure, high safety, and long-term reliability. They typically feature swing or dual-disc designs, robust construction, and rigorous testing (e.g., API 598), making them suitable for oil and gas pipelines, refining facilities, and petrochemical plants. JIS Standards: Primarily based on JIS B2072 and B2082, JIS standards are widely used in Japan and across Asia. Their dimensions are highly compatible with ISO standards, offering compact and lightweight designs. These valves are commonly applied in shipbuilding, general industrial machinery, water treatment, and building pipeline systems. DIN Standards: Representing the European industrial system, DIN standards are centered on the DIN 3356 series (for check valves) and DIN EN series. They are widely used in process industries such as chemicals, pharmaceuticals, energy, and water treatment, emphasizing interchangeability with European pipeline components. GOST Standards: Following specifications like ГОСТ 27477, GOST standards are mandatory in Russia and CIS markets. Their structural dimensions and pressure ratings form a unique system, generally not interchangeable with API, DIN, or JIS standards. Compliance with GOST is essential for entering energy and chemical projects in these regions.