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Company introduction

Hebei Liyong Flowtech Co., Ltd. is a leading manufacturer and exporter of valves, fittings, flanges, pipes and other piping products. Our company is located in the North China Plain of China, which is rich in resources and rich in industrial heritage. We specialize in the manufacture of a wide ra... Read More

Valves

A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fittings, but are usually discussed as a separate category. In an... Read More

Casting Materials of Valves

Casting Materials of Valves ASTM Casting Materials Material ASTM Casting SPEC Service Carbon Steel ASTM A216 Grade WCB Non-corrosive applications including water, oil and gases at temperatures between -20°F (-30°C) and +800°F (+425°C) Low Temp Carbon Steel ASTM A352 Grade LCB Low temperatu... Read More

Old and new DIN Designations

Old and new DIN Designations Over the years, many DIN standards were integrated into the ISO standards, and thus also a part of the EN standards. In the cource of the revision of the European standards serveral DIN standards were withdrawn and replaced by DIN ISO EN and DIN EN. The standards used... Read More

Introduction to Valve Actuators

Introduction to Valve Actuators Valve Actuators Valve actuators are selected based upon a number of factors including torque necessary to operate the valve and the need for automatic actuation. Types of actuators include manual handwheel, manual lever, electrical motor, pneumatic, solenoid, hydra... Read More

Generic Marking Standards and Requirements for valves, fittings, flanges

Generic Marking Standards and Requirements Component Identification The ASME B31.3 Code requires random examination of materials and components to ensure conformance to listed specifications and standards. B31.3 also requires these materials to be free from defects. Component standards and spec... Read More

Torque Tightening for flange

Torque Tightening To obtain a leak-free flange connection, a proper gasket installation is needed, the bolts must be assign on the correct bolt tension, and the total bolt strength must be evenly divided over the whole flange face. With Torque Tightening (the application of preload to a fasten... Read More

Flanges Gaskets & Bolts

Flanges Gaskets & Bolts Gaskets To realize a leak-free flange connection gaskets are necessary. Gaskets are compressible sheets or rings used to make a fluid-resistant seal between two surfaces. Gaskets are built to operate under extreme temperature and pressures and are available in a wide ... Read More

Flange Face Finish

Flange Face Finish Flange face finish The ASME B16.5 code requires that the flange face (raised face and flat face) has a specific roughness to ensure that this surface be compatible with the gasket and provide a high quality seal. A serrated finish, either concentric or spiral, is required wi... Read More

Flange Faces

Flange Faces What is a Flange face? Different types of flange faces are used as the contact surfaces to seat the sealing gasket material. ASME B16.5 and B16.47 define various types of flange facings, including the raised face, the large male and female facings which have identical dimensions to... Read More

Types of Flanges

Types of Flanges Flange types As already described before, the most used flange types ASME B16.5 are: Welding Neck, Slip On, Socket Weld, Lap Joint, Threaded and Blind flange. Below you will find a short description and definition of each type, completed with an detailed image. Most common flang... Read More

Pressure Classes of Flanges

Pressure Classes of Flanges Forged steel flanges ASME B16.5 are made in seven primary Pressure Classes: 150 300 400 600 900 1500 2500 The concept of flange ratings likes clearly. A Class 300 flange can handle more pressure than a Class 150 flange, because a Class 300 flange are co... Read More
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