Danfoss KVP Series - User Manual

max.
100 °C
(212 °F)
max.
140 °C
(285 °F)
max.
140 °C
(285 °F)
3Nm (nger tight
+ 1/4 turn
3Nm (nger tight
+ 1/2 turn)
NB! Tightening torques
must be respected
especially when used
with ammable refrigerants
15% Ag 15% Ag 15% Ag
KVP KVL KVR KVD KVC
Refrigerants:
R22, R1270*, R134a, R290*, R404A, R407A, R407C, R407F,
R448A, R449A, R450A, R452A, R507A, R513A, R600*,
R600a*
* Applicable for KVP 12 – KVP 22, KVL 12 – KVL 22,
KVR 12 – KVR 22, KVD 12 – KVD 15, KVC 12 – KVC 22
For complete list of approved refrigerants,
visit www.products.danfoss.com and search for
individual code numbers, where refrigerants are listed
as part of technical data.
Installation guide
Pressure regulating valve
KVP, KVL, KVR, KVD, KVC
034R9506 034R9506
© Danfoss | DCS (rja) | 2017.03
DKRCC.PI.HA0.A6.00 | 1

Summary

Pressure Regulating Valves Installation

Compatible Refrigerants List

Lists approved refrigerants for KVP, KVL, KVR, KVD, KVC valves.

Valve Type Identification

Visual overview of KVP, KVL, KVR, KVD, KVC valve configurations.

Tightening Torque Specifications

Critical instructions on proper tightening torques for valve installation.

Valve Technical Specifications

Pressure and temperature limits for KVP, KVL, KVR, KVD, KVC valve types.

Valve Size and Pressure Ratings

Details specific valve sizes and their associated pressure ratings.

Overview

1. Function Description
2. Important Technical Specifications
3. Temperature and Pressure Ratings
4. Usage Features
5. Adjustment Ranges
6. Connection Types
7. Maintenance Features
8. Tightening Torques
9. Temperature Limits for Brazing

This document describes the Danfoss Pressure Regulating Valve series, including KVP, KVL, KVR, KVD, and KVC models, designed for various refrigeration applications. These valves are essential components in refrigeration systems, providing precise control over pressure to ensure optimal system performance and efficiency.

Function Description

The Danfoss Pressure Regulating Valves are designed to maintain a constant pressure in different parts of a refrigeration system. Each valve type serves a specific pressure regulation function:

• KVP (Evaporating Pressure Regulators): These valves maintain a constant evaporating pressure in the evaporator. By preventing the evaporating pressure from dropping below a set value, KVP valves ensure stable evaporator operation, prevent icing, and protect the compressor from low suction pressure. They are crucial for applications requiring precise temperature control in the evaporator, such as chillers, air conditioning systems, and cold rooms. The KVP series is available in sizes KVP 12 to KVP 35.

• KVL (Crankcase Pressure Regulators): KVL valves are installed in the suction line before the compressor to limit the crankcase pressure. This prevents the compressor from overloading during start-up or after defrost cycles when the evaporating pressure might be high. By maintaining the crankcase pressure below a safe limit, KVL valves protect the compressor motor from excessive current draw and potential damage. The KVL series is available in sizes KVL 12 to KVL 35.

• KVR (Condensing Pressure Regulators): These valves regulate the condensing pressure by controlling the flow of refrigerant to the condenser. KVR valves ensure a stable condensing pressure, especially in systems with varying ambient temperatures, such as those used in winter operation. By maintaining an adequate pressure difference across the expansion valve, they ensure proper liquid supply to the evaporator and prevent flash gas. The KVR series is available in sizes KVR 12 to KVR 35.

• KVD (Discharge Gas Bypass Regulators): KVD valves are used to bypass hot discharge gas directly into the evaporator or suction line. This is typically done to maintain a minimum evaporating pressure during periods of low load, preventing the evaporator from freezing up and ensuring stable operation of the compressor. They are particularly useful in systems with multiple evaporators or fluctuating heat loads. The KVD series is available in sizes KVD 12 to KVD 22.

• KVC (Condensing Pressure Regulators with Differential Pressure Function): KVC valves are similar to KVR valves but are designed to maintain a constant differential pressure across the condenser, ensuring stable operation even with varying loads or ambient conditions. This helps to optimize the subcooling and efficiency of the system. The KVC series is available in sizes KVC 12 to KVC 22.

Important Technical Specifications

The Danfoss Pressure Regulating Valves are compatible with a wide range of refrigerants, including R22, R1270*, R134a, R290*, R404A, R407A, R407C, R407F, R448A, R449A, R450A, R452A, R507A, R513A, R600*, and R600a*. The refrigerants marked with an asterisk (*) are applicable for specific valve sizes: KVP 12-22, KVL 12-22, KVR 12-22, KVD 12-15, and KVC 12-22. For a complete list of approved refrigerants and their compatibility with specific code numbers, users are directed to www.products.danfoss.com.

Temperature and Pressure Ratings:

• KVP, KVL, KVR, KVD, KVC:
  • Maximum operating temperature (tmax): 130 °C (265 °F)
  • Minimum operating temperature (tmin):
    • KVP: -45 °C (-50 °F)
    • KVL: -60 °C (-75 °F)
    • KVR, KVD, KVC: -45 °C (-50 °F)
  • Maximum working pressure (PS/MWP):
    • KVP, KVL: 18 bar (260 psig)
    • KVR, KVD, KVC: 28 bar (406 psig)

Usage Features

The valves are designed for ease of installation and adjustment. They feature robust construction suitable for demanding refrigeration environments.

Adjustment Ranges:

• KVP 12, 15, 22, KVL 12, 15, 22, KVC 12, 15: Adjustable over 360° for approximately 0.45 bar (6 psi).
• KVP 28, 35, KVL 28, 35: Adjustable over 360° for approximately 0.30 bar (4 psi).
• KVR 12, 15, 22, KVD 12, 15, 22: Adjustable over 360° for approximately 2.50 bar (36 psi).
• KVR 28, 35: Adjustable over 360° for approximately 1.50 bar (22 psi).

The KVP and KVL series have a nominal pressure (p_e) of 2 bar, while the KVR, KVD, and KVC series have a nominal pressure (p_e) of 10 bar.

Connection Types:

The valves are designed for solder connections, indicated by the 15% Ag (silver) content for brazing. This ensures strong, leak-proof connections in refrigeration lines.

Maintenance Features

The design of these valves emphasizes durability and reliable performance, minimizing the need for frequent maintenance. However, proper installation and adherence to tightening torques are crucial for long-term operation.

Tightening Torques:

• General tightening: 3 Nm (finger tight + 1/4 turn).
• Specific tightening for flammable refrigerants: 3 Nm (finger tight + 1/2 turn). This increased torque ensures a secure seal, which is critical when working with flammable refrigerants to prevent leaks.

Temperature Limits for Brazing:

During brazing, it is important to manage the temperature to prevent damage to the valve components. The maximum temperature for the valve body during brazing is 100 °C (212 °F) for the KVP series and 140 °C (285 °F) for the KVL, KVR, KVD, and KVC series. This ensures that internal components are not compromised by excessive heat.

Overall, the Danfoss Pressure Regulating Valves offer a comprehensive solution for precise pressure control in various refrigeration and air conditioning applications, combining robust design with ease of use and broad refrigerant compatibility.

Danfoss KVP Series Specifications