METER TUBE WITH CENTRIC ORIFICE PLATE
Meter tube is a complete set consisting of a centric orifice plate and straight lengths of piping on its inlet and outlet side. Meter tube is a construction of three sections: inlet, in which the fluid flow is straightened, measuring one (orifice plate) and outlet.
Straight lengths of the meter tube comply with all shape conditions and geometric accuracy defined by ISO 5167 standard, related to piping sections adjoining to the orifice plate. This setting ensures entrance of stabilized fluid flow into primary element and accurate measurement of flow mass. Conception of meter tubes also minimizes eventual non-conformities of the orifice plate fittings and their subsequent operation. Division of the meter tube to particular sections also enables easier maintenance control or subsequent meter verification.
Differential pressure tapping is chamber and integrated directly in the flange bodies, between which a disc of the orifice plate is placed and sealed. The disc is thoroughly centred between the flanges by a simple design placement. The meter tube set contains stainless distance bolts placed in the flanges that are gripping the disc. These distance bolts significantly facilitate dismantling and subsequent assembly of the disc. Pressure tapping is led out of the flanges. Upon agreement with the customer, outlets of differential pressure are always customized to various options of primary element attachment to the measuring circuit.
The meter tube with centric orifice plate is manufactured in nominal diameters ranging from DN 50 up to DN 1, 000. Standard meter tube with centric orifice plate in nominal diameters ranging from DN 50 up to DN 150 is manufactured with straight lengths of the piping 10D “downstream” and 5D “upstream” the orifice plate. 2D section “downstream” the orifice plate is separated by a flanged joint and it is detachable for the purpose of its comfortable accessibility during its inspections. Process connection of meter tube is placed on both ends with preparation for its welding as a standard. On agreement with customers it can be manufactured as a flanged one, too.
The meter tube with centric orifice plate in nominal diameters DN 200 and higher is manufactured as a standard with straight lengths of piping 2D “downstream” the orifice plate and 2D “upstream” it. 2D section “downstream” the orifice plate is ended with a flange and it can be supplemented with a counter-flange including supply of fasteners and seals, 2D section “upstream” the orifice plate is ended by preparation for its welding. Upon agreement with customers ending of 2D section “upstream” the orifice plate can be manufactured as a flange. The meter tube can also be equipped with 8D section with metrological verification supplementing inlet section “downstream” the orifice plate to total length of 10D.
Carbon, stainless or refractory alloyed steel are the most used steels for the production of meter tubes. The disc of the centric orifice plate is made of stainless steel as a standard. Upon agreement the meter tube can be manufactured of the plastic material, too.
The meter tube with centric orifice plate is manufactured either as a working meter or, as a specified meter with metrological verification complying with the technical particulars and conditions of pattern approval.
Upon agreement the meter tube with centric orifice plate can be manufactures with extended straight sections of piping, or, in DN ranges different than stated above. The meter tube with centric orifice plate can be incorporated both in vertical and horizontal piping.