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The Differences Between Forged Valves and Casted Valves From: NAFCO | China Brass Valves Manufacturer Casting valves are valves made by casting. Generally, the pressure of the cast valves is relatively low (such as PN16, PN25, PN40, but sometimes high pressure can reach 1500Lb, 2500Lb, most of the caliber is more than DN50. Forged valves are forged by machinary, generally used on high-grade pipelines, with small calibers, generally below DN50.                                                       Casted brass bibcock   Casting      1. Casting: It is the process of smelting metal into a liquid that meets certain requirements and pouring it into the mold. After cooling and solidifying and clearing, a casting (part or blank) having a predetermined shape, size and performance is obtained. The basic process of the modern machinery manufacturing industry.        2. The blank produced by casting has low cost, and it can show its economicality for parts with complicated

NAFCO | Endurance Test of Brass Ball Valves  From: NAFCO | Brass Valves China Manufacturer Endurance test. also named as life test, is a method to check whether the brass ball valves can reach the requirements of using times. The test effected through automatic equipment, by opening and closing the brass ball valves. Here below we will explain how the test is carried out. 1. Principle The manual actuator of the valve shall withstand a series of operating cycles as specified in Table below: 2. Test installation An automatic test rig that ensures that the closing torque remains constant and is not effected by the influence of the moment of inertia of the equipment during test. Equipment related forces that act horizontally or vertically onto the headwork and might result in abnormal wear ought to be eliminated. A frictionless connection to the operating spindle shall be ensured. 3. Test 3.1 Conditions Apply a closing torque according to Table 7. With the bal

NAFCO | Hydraulic Test of Brass Ball Valves  From: NAFCO | China Brass Ball Valves Manufacturer Hydraulic tests are basic and important tests for brass ball valves, which ensures the brass ball valves are qualified of flow tightness, as well as the construction strength of brass ball valves, here we go with test details: 1. Leak-tightness test 1.1.Principle This test shall verify the leak-tightness of the ball (internal tightness) and the ball valve assembly (external  tightness) under cold water pressure. 1.2 Test Install the ball valve in a test rig capable of maintaining the static pressures indicated in Table 1 below. For test 1, close the ball using a torque which is not greater than the values in Table 2 below. Subject the ball valve to the pressures indicated in Table 1. 1.3 Requirement The ball valve shall be leaktight at the pressures indicated in Table 1. 1.2 Hydraulic strength 1.2.1 Principle This test shall verify that the ball valve wi

NAFCO | Bending Test of Brass Ball Valves From: NAFCO | Brass Ball Valves Manufacturer China Bending Test is to check the torgue strength of brass ball valves from vertical side, it's very basic test for brass ball valves. There two ways of arrangements for bending Test of Brass Ball Valves: for straight brass ball valve and angel brass ball valves. 1. Bending moment MF1 at the axis of the closure member a) Use the same brass ball valve and the same arrangement as for the torque test; b) apply force F, for 10 s at 1 m from the axis of the closure member so that the bending moment MF1 is produced; c) with the stress removed, measure the external and internal leak-tightness The stress MF1 represents the installation stress. The stress MF2 represents the stress to which the valve may be submitted during service. 2. Bending moment MF2 at the axis of the closure member a) Apply MF2 (see Table 9) for 900 s to the same valve as for the bending moment test

NAFCO | Torque Test of Brass Ball Valves Time:2018-08-09 From: NAFCO | Brass Valves China Manufacturer The tests described are type tests (laboratory tests) and not quality control tests carried out during manufacture. Tests shall be carried out in the sequence of this standard on the same brass ball valve. All tests shall be carried out with cold water of (20 ± 5) °C. The brass ball valve shall not be leaking or broken during the test, failing which the ball valve is not qualitified. 1.1.1 General Hold the ball valve in a rigid fixture as shown in Figure 1. a) All tests shall be carried out with connections to the valves (whatever their end fitting configurations) which are capable of withstanding the required torque values and bending moments (according to Table 1); b) if the inlet and outlet connection are not on a common axis, the torque tests shall be repeated with the connections reversed; c) ensure that the bending and torsional moments can be attained

NAFCO | Brass Gate Valve Installation From: NAFCO | China Brass Valves Manufacturer 1. The installation of the gate valve must be carried out by qualified operators. The deviation of the different axial directions of the two ends of the pipeline must not be too large, otherwise excessive pipeline installation stress will be generated, resulting in failure and damage. The thread precision and effective length strictly enforce the ISO228-1 relevant standards.    When installing the screw, the hex or octagonal part of the same side of the thread should be clamped. The hexagonal or octagonal part of the other end of the valve should not be wrenched to avoid deformation of the valve. It must be made of Teflon tape or thread sealant seal.     2. To install the tightening valve, you must use the corresponding torque wrench or pipe wrench, and screw in the effective thread length. Do not excessively cause the inner end surface to be pressed, causing the sealing surface to b

NAFCO | Definition and Structure of Brass Gate Valves Time:2018-08-02 From: NAFCO | China Brass Gate Valves Manufacturer Brass gate valves are one of the most commonly used plumbing valves for household application, just little smaller than brass ball valves. Brass gate valve is  metal-metal sealed valve and are currently widely used in water supply systems.    Today we're going to explain what is a brass gate valve, what's the structure of brass gate valves:     1. Definition and of Brass Gate Valves   Brass gate valves, also called brass disc valves, are valves in which the closing valve disc moves in the vertical direction along the centerline of the passage, used to turn the media on or off.   The brass gate valve is a control unit that moves the gate plate along the axis of the channel in the vertical direction and shuts off the medium flow control unit through the handwheel rotation drive. The utility model has the advantages of small fluid res