SAFETY


BS&B’s new IDV Safety Valve


to change direction,” says Brazier. “T e design allows for a certain amount of fl ow expansion, but we don’t have nearly the same level of turbulence inside the valve, which increases the capacity of the device.”


By having the inlet diameter match the nominal size of the valve, there is more fl ow [capacity]. T e valve can also be more compact, lighter in weight, and requires smaller size and therefore less expensive piping. T e result is simplifi ed installation and a lower total cost of investment.


A NEW APPROACH


NOVEL SAFETY RELIEF VALVE DESIGN


Latest addition to relief valve arsenal off ers easy installation, increased capacity and cost savings


F


or centuries, safety relief valves have served as a vital line of protection against excessive overpressure that – left unaddressed – can cause considerable damage to industrial processes including equipment failure and process upset, along with secondary hazards arising from an uncontrolled release of pressurised fl uid. T ese essential safety devices are designed to automatically open when the force exerted by the pressure reaches a setpoint to rapidly discharge the fl uids. Once the overpressurisation has dissipated, the valve recloses, conserving the remaining fl uid. In developing codes and standards, the


industry has largely standardised around the 90° fl ow path design outlined by the American Petroleum Institute (API). T is standardised approach requires a drop in pressure inside the valve before it discharges fl uid from the exit nozzle. To ensure proper performance, the orifi ce diameter at the inlet side is smaller than the nominal valve size, with an outlet


diameter that is larger than both. A 2in by 3in traditional API confi guration safety relief valve will be designed with either a 0.785in diameter H orifi ce or a 1.287in diameter J orifi ce at its inlet and a 3in outlet, for example. While it may be convenient for the purposes of standardisation, other approaches to safety relief valve design are possible while meeting industry codes and standards such as those published by T e American Society Of Mechanical Engineers (ASME), says Geof Brazier, managing director, BS&B Safety Systems. “T e traditional 90° standardised confi guration has the unintended consequence of limiting the amount of fl ow that is possible,” adds Brazier. So, BS&B had a novel idea: what if the safety relief valve was an inline device, with outlet and inlet connections that were the same size and an inlet orifi ce diameter to match the inlet connection? “With an inline design, the fl ow


moves in a straight line and doesn’t have


To address the need for increased fl ow, BS&B has introduced the IDV Safety Valve, a self-reclosing safety pressure relief valve that functions the same as a traditional safety relief valve but with an inline confi guration rather than the traditional angle body confi guration. T e inline confi guration allows for up to three times the capacity of a conventional valve. T e smaller the nominal size, the greater the capacity benefi t from the IDV Safety Valve. T is new technology enables customers to achieve the same overall outcome as a traditional valve. T e increased capacity allows engineers and operators to optimise their pressure safety systems and, in many applications, reduce the piping confi guration (line size) by one or more nominal sizes.


T e new valve is compact and


lightweight and can be installed using ANSI/ASME B 16.5 and international fl ange connections. Mounting can be either horizontal or vertical, adding to the fl exibility of application for this design. T e set pressure levels are independent of backpressure, meaning the valve is suitable for variable backpressure applications. T e valve can be combined with an optional integrated rupture disc at the inlet and/or outlet. T e combination of a rupture disc device with a safety relief valve has many benefi ts arising from valve isolation to the normal process conditions including optimal leak tightness, increased operating pressure, extended valve life, and reduced valve maintenance. T e IDV has already been installed in


over 10,000 processes worldwide, making it an established alternative to the safety relief valve that meets the same codes and standards.


www.engineerlive.com 41


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52