ST500 Series ‘Universal’ Orifice Plates
Universal orifice plates are used within orifice meters (see Roto-Boss™ brochure), some types of Orifice Flange Unions and also in Annular Chambers. They are termed as “universal” as they are manufactured to industry standard outer diameters and plate thicknesses to comply with measurement standards such as MFC-3M, ISO 5167 and AGA 3.
Features
As with any orifice plate application, there are a few types of bore inlet depending upon the flowing medium that is being measured. Below is a reference guide based for orifice plate inlets based on flowing medium;
| Flowing Medium | Square edge orifice | Quarter circle or conical entrance orifice | Eccentric orifice | Segmental orifice | |
| Gas | clean | ++ | – | + | + |
| dirty | – | – | ++ | ++ | |
| Liquid | clean | ++ | ++ | + | + |
| viscous | ++ | ||||
| dirty | – | – | ++ | ++ | |
| corrosive | + | + | + | – | |
| Steam | + | + | + | – |
++ preferred + suitable – not suitable
| Nominal Pipe Size | Plate O.D in inches | Plate Thickness |
| 2” | 2.437 | 0.125 |
| 3” | 3.437 | 0.125 |
| 4” | 4.406 | 0.125 |
| 6” | 6.437 | 0.125 |
| 8” | 8.437 | 0.250 |
| 10” | 10.687 | 0.250 |
| 12” | 12.593 | 0.250 |
| 14” | 14.000 | 0.250 |
| 16” | 16.000 | 0.375 |
| 18” | 18.000 | 0.375 |
| 20” | 20.000 | 0.500 |
| 24” | 24.000 | 0.500 |
| ORDERING INFORMATION | Part number format for ordering is as follows; SIZE-ANSI-TYPE-BORE-MTL |
| Size | 0.5” – 24” (other sizes available upon request) |
| ANSI | 150, 300, 600, 900, 1500 & 2500 |
| Bore | ‘d’ dimension in inches (provided by the customer or sized by calculation) |
| Hole (if required) | V = Vent, D = Drain |
| MTL | 304 = 304 St. Steel 316 = 316 St. Steel D = Duplex SD = Super Duplex M = Monel I = Inconel |
| WORKED EXAMPLES | Note: “V” or “D” is indicated in the part number only if a Vent or Drain is required |
| ST500OP-14-150-SQC-0.5-316 | 14” 150 ANSI, Square Edge Concentric with a 0.5” bore in 316 St. Steel |