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It came to our attention earlier this year that some safety valves containing Thermodiscs (e.g., Consolidated 1811 and Consolidated 1711 series) were being put through hydrostatic testing. These valve parts are designed for steam service only and water can cause damage, potentially beyond repair. This article describes the problems that hydrostatic testing can cause and what you can do to mitigate these problems.


The American National Standards Institute (ANSI) and the International Society of Automation (ISA) provide standards for the hydrostatic testing of control valves. The goal of the test is to verify the valves’ structural integrity and leak tightness. This article summarizes the fluid, pressure, and time requirements of hydrostatic testing as well as the standards for acceptable performance.


To work properly when they’re needed, all valves must be maintained. It used to be that preventative maintenance was the only option. But with the diagnostic tools available today, it’s possible in some cases to use a data-based predictive approach instead. Both of these approaches are part of an effective valve disc maintenance program. This article helps you understand when each of them is most appropriate.


Sand casting can be used for the majority of metals. Even highly reactive magnesium is sand cast provided care is taken and the correct materials used by adding what are called inhibitors into the sand.






Sand castings inevitably have a slow cooling rate because of the large insulating mass of sand surrounding the liquid metal as it cools. Grain sizes and dendrite arm spacings tend to be larger than in equivalent section sizes in die-castings.


Sand casting involves the pouring of molten metal into a cavity-shaped sand mould where it solidifies (Fig. 6.8). The mould is made of sand particles held together with an inorganic binding agent. After the metal has cooled to room temperature, the sand mould is broken open to remove the casting. The main advantage of sand casting is the low cost of the mould, which is a large expense with permanent mould casting methods. The process is suitable for low-volume production of castings with intricate shapes, although it does not permit close tolerances and the mechanical properties of the casting are relatively low owing to the coarse grain structure as a result of slow cooling rate.


The goal of this experimental study is to manufacture a bolted GFRP forged flange connection for composite pipes with high strength and performance. A mould was designed and manufactured, which ensures the quality of the composite materials and controls its surface grade. Based on the ASME Boiler and Pressure Vessel Code, Section X, this GFRP flange was fabricated using biaxial glass fibre braid and polyester resin in a vacuum infusion process. In addition, many experiments were carried out using another mould made of glass to solve process-related issues. Moreover, an investigation was conducted to compare the drilling of the GFRP flange using two types of tools; an Erbauer diamond tile drill bit and a Brad & Spur K10 drill. Six GFRP flanges were manufactured to reach the final product with acceptable quality and performance. The flange was adhesively bonded to a composite pipe after chamfering the end of the pipe. Another type of commercially-available composite flange was used to close the other end of the pipe. Finally, blind flanges were used to close both ends, making the pressure vessel that will be tested under the range of the bolt load and internal pressure.


In manufacturing of the steel bridge, fillet welded T-joint is widely used and angular distortion is often generated. So, reduction or control of angular distortion without additional processes to welding is strongly demanded because it takes great time and effort to correct the angular distortion. In this study, the effectiveness of welding with trailing reverse-side flame line heating for preventing angular distortion was investigated through the welding experiment and numerical simulation in submerged arc welding of fillet T-joint with three different thick flange plate. First, the heat source models for numerical analysis of both submerged arc welding and flame line heating were constructed based on the comparison with the measured temperature histories and angular distortion. And then, these heat source models were used in combination with various kinds of distance between two heat sources to make clear the appropriate distance condition for smallest angular distortion was 150 mm, and it does not depend on thickness of flange plate. It was also confirmed that the experimental angular distortions were in good agreement with those calculated. With a focus on the influence of thickness of flange plate, the reduction of angular distortion by welding with trailing reverse-side flame line heating becomes smaller with increasing thickness of flange plate. However, angular distortion could be adequately prevented under the appropriate flame line heating condition in either thickness of flange plate because the welding-induced angular distortion also becomes smaller with increasing thickness of flange plate. Thus, it was concluded that welding with trailing reverse-side flame line heating could be useful for preventing angular distortion of fillet T-joint, which is a component of steel bridge, enough not to correct it after welding.


Garlock offers a range of Butterfly Valves for different applications. Ranging from GAR-SEAL Butterfly Valves are used extensively where corrosive, abrasive and toxic media, to STERILE-SEAL valves are used in applications where sterile processes need to be maintained in the pharmaceutical and food industries.


Depending on your application, different air valve material and design type should be used. For a better understanding on which type of Garlock Butterfly Valve will best fit the application, you can refer to our Chart