Frese OPTIMA Compact Pressure Independent Control Valve DN 10-50

Overview

The Frese OPTIMA Compact is a pressure independent balancing and control valve (PIBCV) from Frese A/S of Denmark. It is used in heating and cooling systems with fan coil units, chilled beams and other terminal units, and combines an externally adjustable automatic balancing valve, a differential pressure control valve and a full authority modulating control valve in one body. The DN 10 to DN 50 range covers flows from 30 l/h to 11,500 l/h and operates up to 800 kPa differential pressure and suits projects that specify a European make PICV at each fan coil.

Seven Star LLC supplies the Frese OPTIMA Compact, its thermic and motoric actuators and coupling sets to consultants, fan coil manufacturers, MEP contractors and facility teams across Oman and the GCC. Our engineers in Muscat convert fan coil schedules into the correct type, stroke and presetting for each valve and provide the manufacturer data sheet for submittals.

Operating Principle

The Frese OPTIMA Compact design separates two movements that conventional PICVs often mix together. During presetting, the inlet area of the valve moves radially, which sets the maximum flow without shortening the stroke. During modulation, the inlet area moves axially and uses the full stroke of the actuator. As a result, the Frese OPTIMA Compact keeps full stroke modulation and 100 percent authority at every presetting, so a valve set to a low design flow still gives the controller its full resolution. At the same time, the diaphragm-based differential pressure controller holds the pressure across the modulating component constant, so the preset maximum flow is never exceeded regardless of pressure fluctuations up to 800 kPa.

The datasheet curves show the practical effect: at a preset of 300 l/h or 150 l/h, flow stays flat from the minimum differential pressure up to 800 kPa, and at a fixed control voltage of 3, 7 or 10 V the flow is also independent of differential pressure. The Frese OPTIMA Compact can be flushed and commissioned before the actuator is fitted, using only a simple flow versus presetting table. For lowest energy use, Frese recommends checking the differential pressure at the index valve through the P/T plugs and setting the pump at minimum speed.

Engineering Design of the Frese OPTIMA Compact

Frese OPTIMA Compact DN 10 to DN 32 housings are DZR brass CW602N, and DN 40 and DN 50 are ductile iron GJS-400. The differential pressure controller is made of 40 percent glass-filled PPS, the spring is stainless steel, the diaphragm HNBR and the O-rings EPDM. The pressure class is PN 25, threads follow ISO 228, and the medium temperature range is minus 10 to 120 degrees C, with a stem heater required below 0 degrees C. Glycol mixtures up to 50 percent, ethylene or propylene, are permitted, and Frese recommends water treatment to VDI 2035.

The Frese OPTIMA Compact is offered in male/male (M/M) and female/female (F/F) versions, each with or without P/T plugs, and in low and high flow types with 2.5 mm, 5.0 mm or 5.5 mm stroke on DN 10 to DN 32 and 15 mm on DN 40 and DN 50. Close-off to EN 1349 Class IV is 600 kPa on DN 10 to DN 25 with a 100 N actuator, 800 kPa with a 160 N actuator, 800 kPa on DN 25L to DN 32 with 100 N, and 800 kPa on DN 40 to DN 50 with 400 N. Fitted with the isolation cap, DN 10 to DN 32 valves can isolate up to 10 bar. Actuators connect on M30x1.5 with a minimum force of 100 N.

Key Features

The Frese OPTIMA Compact brings these advantages to terminal unit installations:

• Three functions in one valve: automatic balancing, differential pressure control and full authority modulating control.
• Presetting has no impact on the stroke, so full stroke modulation is available at every preset flow.
• Differential pressure operating range up to 800 kPa, with high flows at low required differential pressure.
• Rangeability above 100:1 and a stepless analogue presetting scale for higher precision.
• Sizes DN 10 to DN 50 covering 30 l/h to 11,500 l/h, in M/M and F/F versions with optional P/T plugs.
• Compatible with normally closed thermic actuators (on/off or 0-10 V) and motoric actuators (0-10 V linear or logarithmic, or 3-point).
• No minimum straight pipe lengths required before or after the valve.
• PN 25 DZR brass or ductile iron housings rated from minus 10 to 120 degrees C.

Industrial Applications

Fan coil units, chilled beams and chilled ceilings, the main duty of the Frese OPTIMA Compact, make up the bulk of terminal loads in Gulf buildings. With the Frese OPTIMA Compact on each unit, the system stays hydronically balanced at full and part load, and no further regulating valves are needed in the branch pipework. If floors are added later to a building fitted with the Frese OPTIMA Compact or the design capacity changes, the existing valves do not need rebalancing, which is valuable in phased hotel, office and residential developments in Muscat. Frese also documents the valve in applications such as fan coil PICV control, chilled beam and chilled ceiling control, calorifiers, plate heat exchangers and underfloor heating circuits.

Lower flows, stable pump pressure and higher delta-T translate into lower chiller and pump energy, which is why the Frese OPTIMA Compact is common in district cooling customer buildings, hospitals, malls and schools across Oman, the Sohar and Salalah free zones and the wider GCC. Seven Star LLC supplies valves, actuators and coupling sets as one coordinated scope and can prepare presetting schedules per unit.

Technical Specifications

Key Frese OPTIMA Compact data from the Frese DN10-DN50 data sheet:

How to Order

To order the Frese OPTIMA Compact, send Seven Star LLC your fan coil or terminal unit schedule or a formal RFQ. Our instrumentation division in Muscat will select types, strokes, actuators and couplings, 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 Danfoss AB-QM PICV, the Grundfos MAGNA3 circulator and the pFlow E5 ultrasonic BTU meter.