Single Chamber Remote Float Valves

Design Features & Main Applications

A typical single-chamber remote float valve, ductile iron body, for waterworks applications.

The single chamber remote float valve is a diaphragm-type hydraulic control valve that has only one control chamber located above the diaphragm. The single chamber design uses line pressure acting from below the valve trim while simultaneously applying pressure through a float mechanism to the control chamber above the diaphragm. The closure member (disc) of the main valve is lifted up and down automatically by line pressure in a direction perpendicular to the piping flow direction. Single chamber remote float valves are primarily used for managing water levels in tanks and reservoirs. They respond to changes in water level, automatically opening or closing to maintain a desired level. This remote operation capability enables centralized monitoring and control, ensuring efficient water management and preventing issues like overfilling or water shortages.

Working Principles

The single chamber remote float valve consists of the double flanged main valve, an angle valve, a float ball, and a float rod, a needle valve, a small built-in strainer, and a union ball valve, a series of hydraulic tubing and fittings, and other components.

Illustration of the operation of a single-chamber remote float valve when the water level falls below its preset value.

Under normal conditions, water enters the main valve’s upper control chamber (2) through the needle valve (1) from the main valve inlet. When the tank’s water level falls below the preset value, the angle valve (4) opens, allowing water from the upper control chamber (2) to discharge into the tank. This discharge causes a drop in pressure within the upper control chamber, which in turn opens the main valve to supply water to the tank.

Illustration of the operation of a SC remote float valve when the water level reaches its preset value.

Conversely, as the water level rises, the float ball (6) gradually closes the angle valve (4). This closure increases the pressure in the upper control chamber, prompting the diaphragm to slowly close the valve disc. Once the water level reaches the preset value, the angle valve shuts completely, and the main valve fully closes, stopping the water supply. Additionally, the needle valve (1) regulates the closing speed to prevent water hammer, and the union ball valve (3) can be manually closed for emergency shut-off if the float ball loses control.

Key Advantages & Technical Specifications

Single-chamber (SC) remote float valves are the most widely used float valves in waterworks applications. Compared to its conventional dual-chamber counterpart, SC remote float valves have the following advantages:

• Simplicity and Reliability: SC valves have a straightforward design with only one control chamber. This simplicity means fewer moving parts and eliminates the need for additional sealing mechanisms that are required in dual-chamber (DC) valves. With no internal seals between the diaphragm and the water, there’s less risk of wear, tear, and leakage. This results in lower maintenance needs and a reduced risk of trim seizure over time.
• Lower Friction and Energy Losses: Because the single chamber design does not require extra seals, the forces resisting the valve opening are lower. This contributes to more efficient operation with reduced energy losses. The downstream pressure assists the opening by acting directly on the disc from below, maximizing the effective lifting force and resulting in a lower minimal operating pressure.
• Cost Effectiveness and Optimal Solution: The simpler design not only reduces manufacturing complexity but also cuts down on spare parts and maintenance expenses. For most water level control & remote open/close functions, the single chamber remote float valve is sufficiently efficient.

Typical drawing of the single chamber remote float valves.

The single chamber remote float valves are designed and manufactured in accordance with CJ/T 219, JB/T 10674, and BS EN 558. These valves are furnished with double flanged ends as per EN 1092-2 PN 10 & PN 16. Both the interior and exterior surfaces are FBE coated in accordance with AWWA C550 in RAL 5005 or 5015. They can be used at the temperatures between -10°C and 80°C. Click to view materials, dimensions and flow characteristics of SC remote float valves supplied by Metalsin.