Orifice Plate

Perfect Engineering Services Orifice Plate is a precision instrument used to determine either volumetric flow or mass flow rate as needed. By measuring the fluid flow through the pressure difference from the upstream to the downstream side of a partially obstructed pipe, accurate flow rates can be determined.


The core component of an orifice meter is the Orifice Plate. This plate creates a specific obstruction that narrows the pipe and forces the fluid to constrict, generating a differential pressure that is proportional to the square of the flow rate. The accuracy of flow measurements hinges on the quality of the orifice plate and its proper installation and maintenance.


Our orifice plates are crafted from a variety of materials in compliance with ISO, ISA, AGA, API, and ANSI standards, ensuring reliability and durability.


The Orifice Plate is a simple and cost-effective solution for flow measurement. Essentially, it is a plate with a precisely sized and positioned hole, which can be clamped between flanges in a pipeline. As the fluid passes through the hole, the velocity increases and a pressure drop is developed across the plate. The fluid flow contracts to its smallest diameter, known as the vena contracta, just downstream of the orifice.


When fluid (liquid or gas) flows through the orifice, its pressure builds slightly upstream. As the fluid converges to pass through the hole, the velocity increases and pressure decreases. At the vena contracta, the velocity peaks and the pressure reaches its minimum. Beyond this point, the flow expands, the velocity decreases, and the pressure increases. The flow rate is then calculated using Bernoulli’s equation, with coefficients derived from extensive research measuring the pressure difference across the plate.


Perfect Engineering Services’ Orifice Plates provide a straightforward, economical, and precise method for fluid flow measurement, making them an essential component in various industrial applications.

Nominal pressure rating: as per customer requirements


B-ratio: 0.20 – 0.75


Accuracy: ≤ ±0.5% of full-scale flow rate


Repeatability: 0.1% of flow rate

Size: 15NB TO 200NB


Connection: Threaded, Flanged (ANSI/ASA/ASME B16.5/PN/NPT/BSP)


Materials: ASTM A193 GR. B7, ASTM A194 CLASS 2H, SS 316, SS 316L, SS 316 TI, SS 304,

PTFE, Aluminium Acrylic, Hastelloy C, and other as per customer requirement.