Manuals+

Danfoss AFPB-F / VFQ 2 (VFQ 21)

Differential Pressure Regulator with Flow Limitation

Description

This is a direct-acting differential pressure regulator with a flow limiter for installation on the return pipe, intended for use in district heating systems. The regulator features a control valve (flange connection) with an adjustable throttle for flow setting, a single-diaphragm actuator, and an internal spring for constant differential pressure.

Main Data:

Ordering Codes

Example: Differential pressure regulator AFPB-F/VFQ 2, DN 65, PN 25, max. 150 °C, differential pressure 0.2 bar

Parts are delivered separately.

VFQ 2 Valves (metal sealing cone)

DN (mm) kvs (m³/h) Tmax. (°C) Code No.
PN 16 PN 25 PN 40
15 4.0 150 200* 065B2654 065B2667 065B2677
20 6.3 150 200* 065B2655 065B2668 065B2678
25 8.0 150 200* 065B2656 065B2669 065B2679
32 16 150 200* 065B2657 065B2670 065B2680
40 20 150 200* 065B2658 065B2671 065B2681
50 32 150 200* 065B2659 065B2672 065B2682
65 50 150 200* 065B2660 065B2673 065B2683
80 80 150 200* 065B2661 065B2674 065B2684
100 125 150 200* 065B2662 065B2675 065B2685
125 160 150 200* 065B2663 065B2676 065B2686

* Temperatures up to 200 °C only with sealing cups.

VFQ 21 Valves (soft sealing cone)

DN (mm) kvs (m³/h) tmax. (°C) Code No.
PN 16 PN 25 PN 40
15 4.0 150 065B2690 065B2703 065B2713
20 6.3 150 065B2691 065B2704 065B2714
25 8.0 150 065B2692 065B2705 065B2715
32 16 150 065B2693 065B2706 065B2716
40 20 150 065B2694 065B2707 065B2717
50 32 150 065B2695 065B2708 065B2718
65 50 150 065B2696 065B2709 065B2719
80 80 150 065B2697 065B2710 065B2720
100 125 150 065B2698 065B2711 065B2721
125 160 150 065B2699 065B2712 065B2722

Technical Data

AFPB-F Actuators

VFQ 2, VFQ 21 Valves

Nominal Diameter (DN) kvs (m³/h) Max. flow range* (m³/h) Δpsystem (bar) Δp (bar) Δpmax. PN 16 (bar) Δpmax. PN 25, 40 (bar) Nominal pressure Max. temperature VFQ 2 Max. temperature VFQ 21
15 4 0.1 - 1.4 0.05 - 0.5 0.05 - 0.5 16 20 PN 16, 25 or 40, flanges acc. to DIN 2501 Up to 150 °C with metal sealing cone Up to 150 °C with soft sealing cone
20 6.3 0.15 - 2.1 0.15 - 0.3 0.15 - 0.3 16 20
25 8 0.25 - 2.5 0.25 - 0.4 0.25 - 0.4 16 20
32 16 0.4 - 6.5 0.4 - 0.6 0.4 - 0.6 16 20
40 20 0.6 - 10 0.6 - 0.9 0.6 - 0.9 16 20
50 32 0.9 - 16 0.9 - 2 0.9 - 2 16 20
65 50 2 - 25 2 - 3.5 2 - 3.5 16 20
80 80 3.5 - 40 3.5 - 6.5 3.5 - 6.5 16 20
100 125 6.5 - 50 6.5 - 11 6.5 - 11 15 15
125 160 11 - 80 11 - 15 11 - 15 15 15

* Maximum flow depends on the differential pressure (Δp system) across the system (fully open).

Fluid: Water for heating, district heating and cooling systems, min. 5 °C

Valve body material:

Cone material: Stainless steel, material No. 1.4404

Noise coefficient according to VDMA 24422:

Construction and Mode of Operation

The regulator's total differential pressure (Δp) consists of the differential pressure (Δp) across the flow limiter throttle and the differential pressure (Δp system) of the system (actuator-valve). The total differential pressure is transmitted to the diaphragm chamber via impulse pipes and creates a force balanced by the spring force.

Components:

  1. Valve body
  2. Flow limiter throttle
  3. Valve seat
  4. Balancer
  5. Cover
  6. Actuator housing
  7. Diaphragm
  8. Pressure relief valve
  9. Impulse pipe connection
  10. Bellows diaphragm

Principle of Application

Installed on the return pipe.

Indirectly connected heating system.

Installation Positions

Regulators DN 15 - 80 for fluid temperatures up to 120 °C can be installed in any position.

For regulators DN 100-125 and when the temperature exceeds 120 °C (all nominal diameters), they must be installed only on horizontal pipes with the pressure actuators oriented downwards.

Impulse Pipes

Impulse pipes must be installed between the supply pipe and the control actuator. When used with fluids at temperatures between 150 and 200 °C, sealing cups must be used for the impulse pipes. The impulse pipes listed in "Accessories" can be used.

Setting

The flow limiter is set by adjusting the throttle on the limiter. The differential pressure is constant.

Combinations

Example: Differential pressure regulator AFT06/AFPB-F/VFQ DN 65, PN 25, tmax. 150 °C, differential pressure 0.2 bar, range 20-90 °C

Parts are delivered separately.

AFT06 / KF2 / AFPB-F / VFQ 2

Type Code No.
KF3 Adapter 003G1397

Dimensions

VFQ 2, VFQ 21 Valves

Valve DN 15 20 25 32 40 50 65 80 100 125
L (mm) 130 150 160 180 200 230 290 310 350 400
B (mm) 212 212 238 238 240 240 275 275 380 380
Weight (kg) 7 9 10 13 17 22 33 41 60 79

AFPB-F Actuator

Actuator size (cm²) I (mm) ØA (mm) H (mm) Weight (kg)
250 263 150 9

Sealing cup V1

KF2, KF3 Adapter

PDF preview unavailable. Download the PDF instead.

AI000086457958bg-000101 Danfoss A/S

Related Documents

Preview Danfoss ASV Automatic Balancing Valves - Technical Catalog
Comprehensive technical catalog detailing Danfoss ASV series automatic balancing valves, including their applications, features, construction, ordering information, technical specifications, and dimensioning guides for HVAC systems.
Preview Danfoss Stellventile VR, VF und VFS: Datenblatt für Zwei- und Dreiwegeventile
Umfassendes Datenblatt von Danfoss für Stellventile der Serien VR, VF und VFS. Enthält technische Spezifikationen, Anwendungsbereiche, Bestellinformationen und Abmessungen für Zwei- und Dreiwegeventile.
Preview Danfoss AB-QM DN 40-100 Operating Guide
This guide provides operating instructions for the Danfoss AB-QM DN 40-100 automatic balancing and control valve, covering installation, setting, resetting, locking, and measuring procedures.
Preview Danfoss AVQM-2 Flow Rate Controller: Installation and Operation Manual
Comprehensive guide for the Danfoss AVQM-2 flow rate controller, covering installation, operation, settings, troubleshooting, and technical specifications. Includes safety instructions and dimensional data.
Preview Danfoss AFP B(-F) 2 / VFQ 2(1) / VFQ 22(1) Operating Guide
Comprehensive operating guide for Danfoss AFP B(-F) 2 and VFQ 2(1) / VFQ 22(1) control valves, detailing safety, application, assembly, installation, operation, maintenance, and technical specifications.
Preview Danfoss AFQ 2 / VFQ 2(1) / VFQ 22(1) Operating Guide
This operating guide provides detailed instructions for the Danfoss AFQ 2, VFQ 2(1) DN 15-125, and VFQ 22(1) DN 65-250 flow rate controllers. It covers safety precautions, application definition, assembly, installation, dismounting, leak and pressure testing, system start-up, operation, and flow rate adjustment procedures.
Preview Danfoss AB-QM 4.0 Flexo DN 15-20 PN 25 Datasheet
Technical datasheet for the Danfoss AB-QM 4.0 Flexo, a pre-assembled, pressure-independent control valve assembly designed for optimal hydronic balancing in HVAC cooling and heating applications. Features include easy installation, precise flow control, and energy efficiency.
Preview Danfoss AFPA 2 / VFG 2(1) and VFG 22(1) Operating Guide
This document provides operating instructions for Danfoss AFPA 2 / VFG 2(1) DN 15-250 and VFG 22(1) DN 65-250 differential pressure control valves. It covers safety information, application, scope of delivery, assembly, installation, testing, start-up, shutdown, setpoint adjustment, dimensions, and troubleshooting.