Food, Beverages & Hygiene | Equilibar® FD Series

Equilibar FD Series | Back pressure regulators adapted to hygiene-requirements

Equilibar has dedicated its FD series to use in applications related to the food, (bio)pharma and sanitary industries. The FD series regulators work similarly to other Equilibar back pressure regulators. The pressure on the inlet is controlled with a reference pressure on top of the regulator.

The FD Series was developed in a comprehensive development process to achieve optimal draining. The instruments are suitable for Clean-In-Place (CIP) and Steam-In-Place (SIP) and can be flushed in both directions. In chromatography, dosing and injections processes, CIP is commonly required.

Regulators in the FD Series meet the ASME BPE requirements, such as:

Crevice free design
USP class VI certified materials
Electropolished stainless steel
Surface roughness Ra < 0.5 µm
EU 1935/2004 (upon request)

Low flow / low pressure regulators also enabling high CIP flows

The FD Series is available for ultra-low pressure- and flow control applications starting at a Cv of 10^E-7. Low flow applications often require high CIP flows, which is actually resulting in contradicting requirements when selecting the right control valve. This can make it quite difficult for process engineers in hygiene-sensitive environments to find a suitable and adequate valve for their process.

A common solution to work around this issue is to install a CIP bypass line with a pressure relief valve. During the cleaning and rinsing process, the relief valve reduces excess pressure. These bypass loops are adding complexity to the design of the process instrumentation. With regulators in Equilibar’s FD Series, an excellent solution for this type of application is presented: Because the FD Series has a flow turn down ratio of 1:10.000, both low process flows and larger CIP flows are possible and the use of a CIP bypass line can be avoided in the process design with 1 valve only!

Construction

The Equilibar FD series is available with a maximum pressure of 10 bar gauge (150 PSI). It is equipped with two diaphragms. The top diaphragm is the actuation diaphragm. The bottom diaphragm reduces the effect of water hammering, which sometimes occurs at a specific combination of flow and pressure. The diaphragms are available in different materials like PTFE, Buna-N, FKM, and EPDM (UPS class VI). The standard diaphragms allow a maximum temperature of 150 °C. Higher temperatures can be achieved by applying different polymeric- or alloy diaphragms. Body materials are available in Stainless Steel, Hastelloy, Titanium, Monel, and Zirconium. Other materials like PTFE or PVDF are available on request. The valves can be supplied from ½” up to 2” line size with tri-clamp or tube stub fittings. These regulators cover a Cv range from 10^E-7 to 19 with only 5 models.

Available certifications

The FD series back pressure regulators are pressure- and flow tested prior to delivery. When you require additional certification, it is possible to request a Sanitary Certification Package. The package contains verification of valve body materials, diaphragm materials, surface finish, electropolishing, lubricant materials, and pressure leak testing.

Applications

In biopharmaceutical filtration, high-precision pressure control is often needed. When filtrating, a small pressure difference is controlled across a membrane or filter. The FD series are able to deliver superior precision even at a wide range of flow rates. This differential pressure can be set as narrow as 1 psi. Therefore, the FD series can be an excellent solution for biopharmaceutical filtration. Read all about it in this blog, where we zoom in on how filtration applications work.

With product blending, it is important that the blending ratio is constant. These applications often involve flow meters with a flow controller that controls a pump. To reach high precision you need to have constant back pressure. The FD series back pressure regulator is commonly used because of its high precision. A known problem is pressure fluctuations. The cause of the fluctuation cannot always be avoided and result in unstable flow control and therefore inconsistent blending ratios. When using an FD series back pressure regulator you can isolate the supply header from the main header. This solves the problem of pressure fluctuations from influencing flow control equipment.