Just Valves

What is DN by Just Valves Perth? DN stands for ‘Diameter Nominal’.  Put simply, it is a rough translation of mm from imperial sizes, assuming that an inch is 25mm. We refer to a 12″ flange as DN300, when in fact it is 304mm. Please use the table below for your reference and if you have any other questions, please ask the Just Valves team. ½” DN15 ¾” DN20 1″ DN25 1¼” DN32 1½” DN40 2″ DN50 2½” DN65 3″ DN80 4″ DN100 5″ DN125 6″ DN150 8″ DN200 10″ DN250 12″ DN300 14″ DN350 15″ DN375 16″ DN400 18″ DN450 20″ DN500 24″ DN600

What is a knife gate valve by Just Valves Perth? Knife gate valves are designed mainly for on-off and isolation services in systems with high content of suspended solids. The knife gate valves are especially beneficial for handling slurry, viscous, corrosive and abrasive media. The valves have a minimised pressure drop in fully open position, they are easy to actuate, they have a relatively low weight and are cost effective. Knife gate valves are designed to work in some of the most harsh environments, typically having a sharpened blade to cut through heavy liquids. They are especially useful in wastewater applications where corrosion is an important issue. So, in addition to the valve design optimised for slurry media, it is beneficial to have a knife made of acid-proof stainless steel as this makes it less susceptible to damages caused by corrosion and as a consequence it needs less frequent maintenance or even replacement. Knife gate valves should only be used for applications requ...

Globe valves by Just Valves Perth A Globe valves is a linear motion valve and are primarily designed to stop, start and regulate flow. The disk of a Globe valve can be totally removed from the flow path or it can completely close the flow path. Conventional Globe valves may be used for isolation and throttling services. Although these valves exhibit slightly higher pressure drops than straight=through valves (e.g., gate, plug, ball, etc.), they may be used where the pressure drop through the valve is not a controlling factor. Because the entire system pressure exerted on the disc is transferred to the valve stem, the practical size limit for these valves is NPS 12 (DN 300). Globe valves larger than NPS 12 (DN 300) are an exception rather than the rule. Larger valves would require that enormous forces be exerted on the stem to open or close the valve under pressure. Globe valves in sizes up to NPS 48 (DN 1200) have been manufactured and used. Globe valves are extensively employed to...

What is a gate valve by Just Valves Perth? Gate valves are designed for fully open or fully closed service. They are installed in pipelines as isolating valves, and should not be used as control or regulating valves. Operation of a gate valve is performed doing an either clockwise to close (CTC) or clockwise to open (CTO) rotating motion of the stem. When operating the valve stem, the gate moves up- or downwards on the threaded part of the stem. Gate valves are often used when minimum pressure loss and a free bore is needed. When fully open, a typical gate valve has no obstruction in the flow path resulting in a very low-pressure loss, and this design makes it possible to use a pipe-cleaning pig. A gate valve is a multiturn valve meaning that the operation of the valve is done by means of a threaded stem. As the valve has to turn multiple times to go from open to closed position, the slow operation also prevents water hammer effects. Gate valves can be used for a vast number of fluids....

What is a butterfly valve by Just Valves Perth? A butterfly valve is a shut-off valve with a relatively simple construction. In closed position, the disc blocks the valve bore while in open position, the disc is turned to allow flow. A quarter turn takes the valve from fully open to fully closed position, or opposite, and thus the butterfly valve allows for quick opening and closure. Butterfly valves can be used for a broad range of applications within water supply, wastewater treatment, fire protection and gas supply, in the chemical and oil industries, in fuel handling systems, power generation etc. Some of the advantages for this type of valve are the simple construction not taking up too much space, and the light weight and lower cost compared to other valve designs. The valves can be operated by handles, gears or actuators according to any specific need. Main design of butterfly valves The butterfly valve can be centric or eccentric. On a centric (concentric) butterfly valve the ...

Ball Valves by Just Valves Perth A ball valve is a device with a spherical closure unit that provides on/off control of flow. The sphere has a port, also known as a bore, through the centre. When the valve is positioned such that the bore is aligned in the same direction as the pipeline, it is in open position and fluid can flow through it. When rotated 90 degrees, the bore becomes perpendicular to the flow path, meaning the valve is closed and the fluid cannot pass through. The ball valve, along with butterfly and plug valves, is part of the quarter-turn valve family. Ball valves are known for reliable, bubble-tight sealing. Thus, they are a great choice for gas applications where tight shutoff is necessary. Due to the potential of constant wearing on the seats, ball valves are not ideal for throttling applications. The body of a ball valve usually is made of steel and can be more durable with nickel plating.  The most common ball valves are considered to be two-way, which allows...