Frese OPTIMA Compact Veriflow Flanged PICV DN 50-300

Overview

The Frese OPTIMA Compact Veriflow is the flanged pressure independent balancing and control valve (PIBCV) of the Frese range for large HVAC loads such as air handling units, heat exchangers and mixing circuits. It combines an externally adjustable automatic balancing valve, an integrated differential pressure controller and a full authority modulating control valve in one cast body from DN 50 to DN 300. The Veriflow design adds a third P/T plug, so that commissioning teams can verify both the actual flow and the minimum differential pressure across the whole valve. Flows range from 1.4 m3/h on the smallest DN 50 Ultra type to 600 m3/h on DN 250 and DN 300.

Seven Star LLC supplies the Frese OPTIMA Compact Veriflow with matching Frese motoric and spring return actuators to consultants, MEP contractors and plant operators across Oman and the GCC. Our engineering team in Muscat helps choose between Ultra and Standard versions, low and high flow types and PN 16 or PN 25, and provides the manufacturer data sheet for submittals.

Operating Principle

As in the smaller DN 10 to 50 range, in the Frese OPTIMA Compact Veriflow presetting and modulation are two independent movements. Presetting moves the inlet area radially to set the maximum flow, while modulation moves it axially over the full actuator stroke. The valve therefore keeps 100 percent authority and full stroke at every preset flow, and the integrated differential pressure controller holds the preset maximum flow constant up to 800 kPa differential pressure. The Frese OPTIMA Compact Veriflow has a linear control characteristic that is independent of flow setting and available pressure, so the actuator setting can be used to change the valve response from linear to logarithmic (equal percentage) for coil control.

Veriflow measurement uses three P/T plugs. Measuring between the red plug P1 and the blue plug P2 in the middle of the body gives the pressure drop across the Kv presetting, and flow follows from Q equals Kv times the square root of the differential pressure, using the Kv-signal values in the data sheet. Measuring between P1 and the blue plug P3 at the outlet flange gives the differential pressure across the whole valve, which is compared with the required minimum to optimise the pump setting for energy saving. This is a practical advantage on large Frese OPTIMA Compact Veriflow installations, where pump energy is a large share of plant running cost.

Engineering Design of the Frese OPTIMA Compact Veriflow

Frese OPTIMA Compact Veriflow housings are GJL-250 or GJS-400 cast iron with a GJS-400 cover; the DN 50 Ultra uses DZR brass CW602N. The differential pressure controller is stainless steel and PPS on DN 50 to 80 and stainless steel on larger sizes, with stainless steel springs, reinforced EPDM or HNBR diaphragm and EPDM O-rings. Pressure class is PN 16 or PN 25 with flanges to ISO 7005-2 / EN 1092-2. Stroke is 15 mm on the DN 50 Ultra, 20 mm on DN 50 to 80 and on the DN 100 Ultra, 40 mm on DN 100 to 125, 43 mm on DN 150 and DN 200, and 48 mm on DN 250 and DN 300. The medium temperature range is minus 10 to 120 degrees C, reduced to 110 degrees C for PN 25 versions from DN 150 upwards, with a stem heater required below 0 degrees C.

Two versions of the Frese OPTIMA Compact Veriflow are offered. The Ultra version has reduced size and weight for easier installation, for example 10.7 kg against 14.5 kg for DN 50, while the Standard version has higher flows to cover a wider range. Close-off to EN 1349 Class IV is 800 kPa for all sizes, based on 800 N actuator force for DN 50 to 125, 1100 N for DN 150 to 200 and 2000 N for DN 250 to 300. Valves and actuators can be ordered as one item number, and a C5 protective coating option (suffix -ST01) is available for corrosive environments, which is relevant for coastal plant rooms in Oman.

Key Features

The Frese OPTIMA Compact Veriflow offers these advantages for large hydronic loads:

• Three P/T plugs for measuring both flow and minimum differential pressure across the valve.
• Full stroke modulation and 100 percent authority at every preset flow, with rangeability above 100:1.
• Differential pressure operating range up to 800 kPa, with Class IV close-off at 800 kPa.
• DN 50 to DN 300 with Ultra and Standard versions and low and high flow types from 1.4 to 600 m3/h.
• PN 16 and PN 25 versions with flanges to ISO 7005-2 / EN 1092-2.
• Linear characteristic that can be changed to logarithmic through the actuator setting.
• Motoric 0-10 V and 3-point actuators, with spring return options for all sizes.
• Optional C5 protective coating and stem heater for demanding environments.

Industrial Applications

Air handling unit coils, fresh air units, plate heat exchangers and secondary mixing circuits carry most of the flow in a central chilled water plant. Using the Frese OPTIMA Compact Veriflow on these loads keeps each one at its design flow regardless of what the rest of the network is doing, which keeps chiller delta-T up and allows variable speed pumps to run at the lowest safe head. No further regulating valves are needed in the pipework around a Frese OPTIMA Compact Veriflow, and no straight pipe runs are required before or after the valve. Typical Omani projects include hospitals, airport and logistics buildings, shopping malls, hotels and district cooling energy transfer stations in Muscat, Duqm and Salalah.

The PN 25 Frese OPTIMA Compact Veriflow versions suit high-rise towers and district cooling networks with high static pressure, and the C5 coating option helps in coastal and industrial plant rooms in the Sohar and Salalah free zones. Seven Star LLC supplies the Frese OPTIMA Compact Veriflow with matching actuators and stem heaters and can prepare presetting and minimum differential pressure tables for each valve on the schedule, for projects in Oman and across the GCC.

Technical Specifications

Frese OPTIMA Compact Veriflow data from the Frese DN50-DN300 data sheet:

How to Order

For a quotation on the Frese OPTIMA Compact Veriflow, send Seven Star LLC your valve schedule or a formal RFQ with flow, size and pressure class. Our instrumentation division in Muscat will confirm the version, flow type and actuator, share the manufacturer data sheet available for download on this page, and coordinate supply with engineering support for Oman and the GCC. Related products include the Belimo EPIV flanged electronic PICV, the Danfoss VLT HVAC Drive FC 102 and the pFlow E8 ultrasonic BTU energy meter.