Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
  • G01L19/00—Details of, or accessories for, apparatus for measuring steady or quasi-steady pressure of a fluent medium insofar as such details or accessories are not special to particular types of pressure gauges
  • G01L19/0007—Fluidic connecting means

Definitions

• the present invention relates to pressure sensor flanges that comprise elements of a pressure sensor assembly, and in particular to a fitting for use in conjunction with a flange that is capable of substantially isolating the flange from a fluid, the pressure of which is to be sensed by the pressure sensor assembly.
• flanges have been used to convey fluid under pressure to a pressure sensor module.
• Conventional flanges are formed from ferrous metal, typically stainless steel, with passageways to convey fluid from impulse piping to the sensor module. This has caused problems in applications of the pressure sensor assembly with corrosive fluids that react with such flanges.
• the entire flange has been formed from an exotic metal.
• exotic metals found to be suitable include tantalum, titanium, the alloy sold under the trademark Monel, and the alloy sold under the trademark Hastelloy. This solution has broader pressure and temperature application than use of the plastics but is also more expensive.
• SUMM ⁇ RY OF THE INVENTION The present invention relates to a fitting or connector for use in cooperation with the flanges of a pressure sensor assembly to convey fluid under pressure from a source through a passageway in the fitting to a fluid chamber within the pressure sensor assembly.
• the fluid chamber is formed in part by the fitting and in part by the pressure sensor interface of the pressure sensor module.
• the pressure sensor interface is connected to the pressure sensing elements within the pressure sensor module so that pressure applied at the pressure sensor interface is sensed at the pressure sensing elements.
• the fitting substantially isolates the flange from the fluid.
• the fitting is constructed of materials that are substantially chemically noninteractive with or substantially inert with respect to the fluid, typically either an exotic metal or a plastic. Where the application requires the use of exotic metals, use of only a fitting made of such metal avoids the expense of machining the entire flange of the exotic metals.
• the flange may be constructed of stainless steel or other ferrous metal in the conventional manner.
• the standard flange supports the fitting to increase the ability of the plastic fitting to withstand fluid temperature and pressure combinations considerably above those that can be withstood when the entire flange constructed of plastic.
• the fitting is particularly suited for use in that portion of the process industry that uses chlorine or derivative thereof in the process fluid.
• Each of the aforementioned materials that have been found to be suitable for use with such chlorines is suitable for use in construction of the fitting.
• Figure 1 is a side view of a typical pressure sensor assembly showing a pressure sensor module and connected flanges with a fragmentary section view of the sensor module, impulse piping, and one flange having the fitting made according to the present invention installed;
• Figure 2 is an enlarged sectional side view of the fitting in combination with the flange, a portion of the pressure sensor module and the pressure sensor interface;
• Figure 3 is a sectional view taken along line 3--3 in Figure 4, showing an embodiment of the fitting having a plurality of slender passageways to minimize the impact of momentary fluid overpressures;
• Figure 4 is an end view of the fitting shown in Figure 3 showing the face portion of the fitting.
• a pressure sensor assembly is illustrated generally at 10 and includes pressure sensor module 11 with flanges 12 secured to both sides of pressure sensor module 11 by bolts 15 such that each flange 12 faces a pressure sensor interface 14 (shown as an isolation diaphragm) formed in the side of pressure sensor module 11.
• Pressure sensor interface 14 is connected to pressure sensor element or elements such as a diaphragm as shown within pressure sensor module 11 in a manner such that fluid pressure acting on pressure sensor interface 14 is transmitted to the pressure sensor elements. It is understood that only one such flange is necessary to sense pressure, but that two or more such flanges and sensor modules may be used as desired.
• pressure sensor assembly 10 is made according to U.S.
• Patent 3,618,390 which is incorporated herein by reference, and corresponds to the differential pressure transducer assembly unit therein.
• Pressure sensor module 11 and flanges 12 of the instant invention correspond with center housing section 15 and end caps 14 and 16 of Patent 3,618,390, respectively.
• the pressure sensor element of the instant figures corresponds to interior sensing cell assembly 26 of Patent No. 3,618,390 and pressure sensor interface 14 disclosed herein corresponds to isolation diaphragm 44 or 45 in Patent No. 3,618,390.
• Leads 18 in the present invention are connected to suitable readout circuitry and to the interior sensing cell assembly as shown in Patent No. 5,618,390.
• fitting 16 shown in section in the left side of pressure sensor assembly 10 in Figure 1 preferably is duplicated on the right side for differential pressure applications of pressure sensor assembly 10.
• the fitting 16 also may be used with other pressure sensor assemblies, having various types of prcssure sensor elements.
• the longitudinal dimension of fitting 16 is that dimension that is axial to passageway 17 in fitting 16 and perpendicular to end face portion 21.
• Opening 15 in flange 12 couples interface 14 to the exterior of pressure sensor assembly 10 when flange 12 is mated to pressure sensor module 11.
• Opening IS is suitably formed to receive fitting 16 therein.
• Impulse piping 19 is connected at one end to a .passageway 17 which extends longitudinally through fitting 16, and at the other end to fluid vessel 28.
• fluid vessel 28 is typically a pipe as illustrated in Figure 1.
• a means for creating a differential pressure typically an orifice plate is mounted in fluid vessel 2S between the points of connection of impulse piping 19. Fluid pressure from fluid vessel
• Fluid chamber 20 is formed by two cooperative parts, the first part being interface 14 and the second part being the end face portion 21 of fitting 16. Within pressure sensor assembly 10, the fluid being sensed is confined within a volume defined by passageway 17 and fluid chamber 20, thereby substantially isolating flange 12 from the fluid. In order to effect fluid tightness, fluid chamber 20 is sealed adjacent to the juncture of the end face portion 21 of fitting 16 and interface 14.
• an 0 ring 22 is compressed between tapered surface 23 of fitting 16 and a shoulder surface 32 in pressure sensor module 11. Tapered face 23 and shoulder 32 are in alignment when flange 12 with fitting 16 inserted therein is mated to pressure sensor module 11. 0 ring 22 is compressed as flange 12 is securely fastened to pressure sensor module 11, thereby effecting the fluid tight seal.
• fitting 16 must be suitably positioned longitudinally with respect to both flange 12 and pressure sensor module 11.
• groove 29, the side and base of which form an L shape, is formed in flange 12, effectively expanding the diameter of opening 15 where opening 15 intersects inner surface 33 of flange 12.
• Fitting 16 is constructed. with an annular shoulder 24 formed to be closely received by groove 29. Shoulder 24 butts against the base of groove 29 when fitting 16 is inserted into opening 15.
• Fitting 16 is compressibly. held in contact with both flange 12, through the contact at the base of groove 29, and 0 ring 22, through the contact with tapered surface 23, when flange 12 is securely mated to pressure sensor module 11, thereby correctly positioning fitting 16 for effective.
• FIG. 1 shows a set screw arrangement for preventing such rotation.
• a threaded bore 27 is machined in flange 12 so that the axis of threaded bore 27 intersects the longitudinal axis of fitting 16 at a desired angle. Threaded bore 27 extends from opening 15 to the exterior of the flange.
• Set screw 30 is threaded into threaded bore 27 and tightened down against fitting 16 or a key way formed in fitting 16 at the point of contact.
• set screw 30 prevents rotation of fitting 16 caused by fluid pressure fluctua tions. Such rotation may cause undesirable working of impulse piping 19 and disruption of the 0 ring seal for fluid chamber 20.
• set screw 30 additionally is used to fix the longitudinal positioning of fitting 16 in order to effect the seal and establish the volume of fluid chamber 20.
• FIGS 3 and 4 illustrate an embodiment of apparatus 16 for use with impulse piping 19 as shown in Figure 1 in which the first portion of passageway 17 is formed and threaded as shown in Figure 1.
• passageway 17 is not extended through the full longitudinal dimension of apparatus 16, but terminates in a plurality of slender passageways 35, which extend through fitting 16 from the termination of passageway 17 to end face portion 21.
• the material through which slender passageways 17 are bored is preferably the same as the fitting.
• the path of fluid flow from impulse piping 19 is first to passageway 17 and then through the slender passageway 35 to fluid chamber 20.
• Passageways 35 admit sufficient fluid to fluid chamber 20 (shown in Figures 1 and 2) to permit sensing of the fluid pressure.
• passageways 35 act as a buffer by responding relatively slowly to the overpressure, thereby protecting interface 14 from damage.
• fitting 16 is substantially chemically noninteractive with the fluid or substantially inert with respect to the fluid.
• the end face portion forms one portion of the chamber which receives the fluid to be sensed and the 0 ring seal closes off any contact of the corrosive fluid being sensed with the flange.
• Interface 14 is a flexible isolation diaphragm and generally is corrugated for permitting movement when the center sensing diaphragm deflects.
• the fluid movement in passageway 17 occurs only during deflection of the sensing diaphragm.
• the fitting preferably is made of a plastic such as tetrafluorocthylene, a plastic sold under the trademark Kynar, titanium, tantalum, or metal alloys sold under the trademarks Monel or Hastelloy, or other suitable material.
• a plastic such as tetrafluorocthylene, a plastic sold under the trademark Kynar, titanium, tantalum, or metal alloys sold under the trademarks Monel or Hastelloy, or other suitable material.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Measuring Fluid Pressure (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=22569728

Family Applications (1)

Country Status (3)

Families Citing this family (3)

Citations (3)

Family Cites Families (4)

• 1981
  • 1981-06-09 JP JP56502165A patent/JPS57500797A/ja active Pending
  • 1981-06-09 EP EP19810901785 patent/EP0053169A4/en not_active Withdrawn
  • 1981-06-09 WO PCT/US1981/000770 patent/WO1981003678A1/en not_active Ceased

Patent Citations (3)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events