| 摘要 |
An orifice fitting with an orifice plate centered in the flow passage of an orifice fitting via direct contact between a cradle and the orifice plate. The orifice plate is centered via the use of an orifice plate carrier having two channels on its downstream side and two slots located in the bottom portion of the seat, which is located on the plate carrier's upstream side. The plate fits into the seat and a bottom portion of the plate's peripheral edge protrudes through the slots. A cradle having locating surfaces fits through the channels in the orifice plate carrier and firmly holds the orifice plate against the orifice plate carrier. The cradle can be positioned and then secured in place by two adjustable set screws and a stem piece of the cradle. Once the orifice plate has been centered via the positioning of the cradle, the stem piece of the cradle and the set screws can be welded into the body of the orifice fitting. Alternatively, the cradle may be formed from weld metal added to the body of the orifice fitting and machined to define the cradle, or can be machined from a portion of the cast metal cradle. The method of the present invention involves the use of a cradle having locating surfaces to center an orifice plate in an orifice fitting by inserting the locating surfaces of the cradle in channels in an orifice plate carrier so that the locating surfaces contact and hold a bottom portion of the peripheral edge of the orifice plate and then positioning the cradle so as to center the plate.
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