Multi-hole orifice plate is similar to centric orifice plate however, in its disc there are more orifice holes. Use of multi-hole orifice plate is limited by β = d/D, the orifice plate is made for β = 0.4 up to 0.65. This orifice plate is mostly placed in a flanged joint. Except for CSN, sealing surfaces of the orifice plates can be manufactured also in compliance with EN, DIN, GOST standards, American ASME and ANSI standards or, on request and specification of the customer.

Multi-hole orifice plate can be manufactured in so-called weld-in design, too. Weld-in design of the multi-hole orifice plate contains straight lengths of piping downstream the disc. Weld placement into the pipe has the advantages such as material savings on the flanges and subsequently minimized leakage in the flanged joint.

Multi-hole orifice plate can be manufactured in design with the meter tube, i.e. as a complete set containing multi-hole orifice plate and straight lengths of piping on the inlet and outlet.

Multi-hole orifice plates are manufactured according to type of differential pressure tapping:

• Orifice plates with corner tapping, i.e. orifice plates with chamber or individual tapping
• Orifice plates with pressure tapping D “downstream” and D/2 “upstream” the disc
• Orifice plates with flanged tapping

Multi-hole orifice plates are manufactured in nominal diameters ranging from DN 15 up to DN 1,000 and depending on the type of pressure differential tapping for nominal pressures up to PN 320.

Upon agreement with customers outlets of differential pressure are always customized to various options of primary element attachment to measuring circuit.

For the production of multi-hole orifice plates depending on type of pressure differential tapping and type of attachment of the orifice plate there is mostly used carbon, refractory alloyed or stainless steel. On agreement multi-hole orifice plate can be made of special materials based nickel and titanium alloys or, tantalum. Orifice plates are made of plastic materials, too.

Multi-hole 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.

Except for advantages of centric orifice plates (such as simplicity, replaceability and reliability), multi-hole orifice plates also has the advantage of smaller installation length enabling wider possibilities of their use. Passage of the measured fluid through several tapered cross-sections reduces demand on minimal straight lengths of piping downstream and upstream the orifice plate necessary for proper functioning of this type of meter (in comparison to centric orifice plate) Multi-hole orifice plate design enables use of straight lengths of piping “downstream” the orifice plate minimally 4D long. Orifice plate with both chamber and individual tapping can be manufactured in DN and PN ranges different than stated above. Multi-hole orifice plate can be incorporated both in vertical and horizontal piping.