Features and Benefits

• Line pressure driven – Independent operation
  ‍
• Modulating hydraulic float control
  - “Always Full” reservoir
  ‍
• Double chamber
  - Full powered closing
  - Non-slam closing characteristic
  - Protected diaphragm
  ‍
• External installation
  - Easy access to valve and float
  - Easy level setting
  - Less wear and tear
  ‍
• Balanced seal disk – High flow capacity
  ‍
• In-line serviceable – Easy maintenance
  ‍
• Flexible design – Easy addition of features

‍

Major Additional Features

• Pressure sustaining – 753-67
• Electric float backup – 750-67-65
• Flow control – 757-67-U
• Level sustaining – 75A-67

‍

Operation

The Model 750-67 is a float controlled valve equipped with an adjustable, 2-Way vertical float pilot assembly. The needle valve [1] continuously allows flow from valve inlet into the upper control chamber [2]. The float [3] is locked on the float assembly rod [4] between two adjustable stoppers [5] and [6]. Should level rise towards setting, the float pilot [7] throttles, pressure in the upper control chamber accumulates causing the main valve to throttle closed, reducing filling rate, and eventually closing drip tight. Should level fall, the float pilot releases pressure from the upper control chamber causing the main valve to modulate open. The needle valve controls the closing speed. Cock valve [8] enables manual closing.

‍

‍

Pilot System Specifications

Standard Materials:

Float Pilot:

Body: Brass or Stainless Steel 316

Elastomers: Synthetic Rubber

Internal parts: Stainless Steel 316 & Brass

Lever system: Brass or Stainless Steel 316

Float: Plastic

Float rod: Stainless Steel

Base plate: Fusion bonded epoxy coated Steel or Stainless Steel 316

Tubing & Fittings: Stainless Steel 316 or Copper & Brass

Accessories: Stainless Steel 316, Bronze, Brass and Synthetic Rubber Elastomers

‍

Notes:

• Rod length: 54 cm (21”)
• Each extension rod adds 56 cm (22”). One extension rod supplied
• Extra counterweight might be required depending on rod length and high operating pressure
• If inlet pressure is below 0.7 bar (10 psi) or above 10 bar (150 psi), consult factory
• Minimum operating pressure: 0.7 bar ; 10 psi. For lower pressure requirements consult factory
• Recommended continuous flow velocity: 0.3-6.0 m/sec ; 1-20 ft/sec

‍

Typical Applications

Rooftop Reservoirs

Rooftop reservoir level control is attained by electric control of the basement pumps according to reservoir level. As overflow of a rooftop reservoir can cause costly damage, hydraulic backup protection is recommended.

Where system design requires an “always full” rooftop reservoir, the Model 750-67 Modulating

Level Control Valve:

• Ensures the reservoir is “always full”
• Closes securely to prevent overflow

Secured closing, even after long periods of the

valve being open, is ensured by the fully developed hydraulic closing force associated with the double chamber design.

‍

Pump Flow Control According to Balancing Reservoir Level

Where well drawdown effects the inflow to a balancing reservoir and outflow varies according to demand, the booster

pump to consumers requires protection against:

• Impeller cavitation
• Pump overload
• Air suction

The Model 75A-67 responds to the balancing reservoir level and provides this protection by dynamically restricting outflow when inflow to the balancing reservoir drops due to drawdown.

‍

Technical Data

Size Range: DN40-900 ; 11/2–36”

‍

End Connections (Pressure Ratings):

Flanged: ISO PN16, PN25 (ANSI Class 150, 300)

Threaded: BSP or NPT

Others: Available on request

‍

Valve Patterns: “Y” (globe) & angle, globe (DN600-900 ; 24”-36”)

Working Temperature: Water up to 80°C ; 180°F

‍

Standard Materials:

Body & Actuator: Ductile Iron

Internals: Stainless Steel, Bronze & coated Steel

Diaphragm: Synthetic Rubber Nylon fabric-reinforced

Seals: Synthetic Rubber

Coating: Fusion Bonded Epoxy, RAL 5005 (Blue) approved for drinking water or Electrostatic Polyester Powder

‍

Differential Pressure Calculation

‍

How to Order

Please specify the requested valve in the following sequence: (for more options please contact us)

• Size
• Main model
• Additional features
• Pattern
• Body material
• End connection
• Coating
• Voltage & main valve position
• Tubing & Fittings materials
• Operational data (according to model)
• Pressure data
• Flow data
• Reservoir level data
• Settings

‍