brands

attributes.Type

attributes.Connection

attributes.Body_Material

attributes.Maximum_Working_Pressure

attributes.Thread_Size

attributes.Thread_Standard

attributes.Flow_Factor_Kv

Spirax Sarco Bronze Single Check Valve, BSPP 1/2in, 14 bar

Spirax Sarco Bronze Sight Glass Check Valve, BSPP 1/2in, 3.6 bar

Spirax Sarco Bronze Single Check Valve, BSPP 1in, 14 bar

Spirax Sarco Brass Sight Glass Check Valve, BSPP 1/2in, 3.5 bar

Spirax Sarco Bronze Sight Glass Check Valve, BSPP 3/4in, 3.6 bar

Spirax Sarco Bronze Single Check Valve, BSPP 3/4in, 14 bar


A check valve, also known as a one-way inline check valve or non-return check valve, is a device that permits the flow of fluids and gases in only one direction within a pipeline system.

These essential components prevent reverse flow, which can lead to contamination of upstream media or damage to sensitive equipment. Their simple, often automated design relies on flow velocity to open or close, ensuring unidirectional movement without human interaction.

## **Types of Check Valves**

### **One-Way Check Valve**

A one-way inline check valve is typically spring-loaded, allowing fluid flow in a single direction. Inlet pressure overcomes the spring force, lifting a disc or ball off its seat to permit flow to the outlet.

This design effectively prevents backflow. For example, an SMC check valve might be used in systems requiring [pneumatic fittings](https://nz.rs-online.com/web/content/discovery/ideas-and-advice/pneumatic-fittings-guide) to maintain pressure or prevent reverse airflow.

### **Double Check Valve**

A double check valve assembly features two independent check valves arranged in series, providing enhanced backflow prevention. If one valve fails or jams open, the other can maintain the seal, significantly increasing reliability.

These non-return check valves are commonly used in applications like fire sprinklers and lawn irrigation systems to prevent back-siphonage and back-pressure contamination.

### **Hydraulic Check Valve**

A hydraulic check valve is a simple yet crucial device designed to permit free oil flow in one direction while completely blocking it in the opposite direction. These valves often incorporate a tapered core for superior sealing performance.

They are essential for maintaining pressure in hydraulic circuits, acting as a single-way lock to ensure fluid integrity and prevent pressure loss.

### **Ball Check Valve**

A ball check valve employs a spherical ball that lifts to allow forward flow and seats against an opening to prevent backflow. Its simple design makes it reliable for various applications, including plumbing systems and pumps, where unidirectional flow is essential.

### **Dual Plate Check Valve**

Dual plate check valves feature two semi-circular plates hinged to swing open with forward flow and close against the seat when flow reverses. Their compact design makes them suitable for applications with limited space, such as HVAC systems and fire protection.

### **Double Door Check Valve**

A double door check valve has two hinged doors that open with forward flow and close rapidly to prevent backflow. This design minimises water hammer and is often preferred in large-diameter pipelines, including water treatment plants and pumping stations.

### **Spring-Assisted Inline Check Valve**

A spring-assisted inline check valve uses a spring to help close the valve quickly when flow diminishes, preventing reverse flow and water hammer. This design allows for flexible mounting orientations and is widely used in pneumatic and hydraulic systems for precise control.

## **Factors to Consider When Choosing a Check Valve**

Selecting the right check valve is essential for ensuring efficient and reliable fluid control. Consider these factors to find a valve suitable for your requirements:

- **Material:** The valve's material must be compatible with the fluid it handles to ensure longevity. For example, opt for a stainless steel check valve if you need high corrosion resistance.
- **Size and pressure rating:** Ensure the valve's size matches your pipeline diameter and that its pressure rating can safely accommodate your system's operating pressure. Incorrect sizing can lead to inefficiency or failure.
- **Installation orientation:** Some one-way check valves have specific installation orientations (e.g., horizontal or vertical) for optimal performance. Confirming this ensures proper operation and prevents backflow issues.
- **Flow characteristics:** Consider how the valve's design impacts fluid flow. Different designs offer varying resistance to flow, which affects system efficiency and pressure drop.

## **Applications of Check Valves**

Check valves are indispensable components across a multitude of industrial applications in NZ, safeguarding systems by ensuring unidirectional fluid and gas flow.

- **Water treatment plants:** These facilities extensively use check valves to prevent backflow of treated or untreated water, ensuring process integrity and preventing contamination.
- **HVAC systems:** In heating, ventilation, and air conditioning systems, one-way inline check valves prevent the backflow of refrigerants or condensate, optimising efficiency and preventing system damage.
- **Fire protection systems:** Crucial for safety, non-return check valves in fire sprinkler and hydrant systems prevent contaminated water from re-entering the main water supply lines.
- **Power generation:** Check valves are vital in power plants for managing water and steam flow, ensuring efficient turbine operation and preventing reverse flow in cooling systems. Stainless steel check valves are often preferred here.
- **Agricultural irrigation systems:** These systems employ check valves to maintain prime in pumps and prevent water backflow, ensuring consistent water delivery to crops and efficient resource use.

## **Your Trusted Check Valve Supplier and Manufacturer in New Zealand**

RS New Zealand is a trusted supplier, manufacturer, and distributor of plumbing and pipeline components, offering a comprehensive range of check valves in various types and materials. Our items are sourced from reputable brands in NZ, such as [SMC](https://nz.rs-online.com/web/b/smc/), [Parker](https://nz.rs-online.com/web/b/parker/), [Legris](https://nz.rs-online.com/web/b/legris/), and [Georg Fischer](https://nz.rs-online.com/web/b/georg-fischer/), ensuring high-quality options for every need.

Beyond specialised valves, we also offer a wide array of other mechanical components like [hose pipes](https://nz.rs-online.com/web/c/plumbing-pipeline/hose-pipe-fittings/hose-pipe-flexible-tubes/) and [water pressure regulators](https://nz.rs-online.com/web/c/pneumatics-hydraulics/pneumatic-air-preparation/pneumatic-regulators/), catering to diverse project needs.

Browse our user-friendly online site to find the product that you need and have it shipped to you with our convenient delivery options. With flexible options available, we ensure that you receive your items when you need them. For more details on delivery times and fees, check out our [delivery information page](https://nz.rs-online.com/web/content/support/all-articles/delivery).



Check Valves

Valves & Taps

Plumbing & Pipeline

Electrical, Automation & Cables

Automation & Control Gear

Automation Signalling

Contactors & Auxiliary Contacts

Electric Motors

Industrial Robots

PLCs, HMIs & Industrial Computing

Process Control

Sensors

Solenoids

Cables & Wires

AV Cables

Cable Glands & Fittings

Cable Joints & Cable Sleeving

Cable Management

Cable Ties & Fixings

Computer Cables

Electrical Power & Industrial Cables

Networking & Coaxial Cables

Single Core Cable

Wire to Board Cables & Ribbon Cable

Enclosures & Server Racks

19-Inch Racking

Enclosures

Enclosures & Racking Components

Fuses & Circuit Breakers

Circuit Breakers

Earth & Lightning Protection

Fuse Holders & Accessories

Fuses

HVAC, Fans & Thermal Management

Air Conditioning & Fans

Air Conditioning & Heating Accessories

Building Automation

Electronics Heating & Cooling Components

Fan Accessories

Heaters & Radiators

Lighting

Light Bulbs, Lamps & Tubes

Light Fittings, Fixtures & Luminaires

Lighting Components

Torches & Inspection Lamps

Relays & Signal Conditioning

Relay Accessories

Relays

Signal Conditioners & Isolators

Switches

Capacitive, Magnetic and Piezo Switches

DIP & Rotary Encoded Switches

Domestic Installation Switches

Foot Switches & Components

Joysticks & Components

Key Switches & Selector Switches

Keyboard & Keypad Switches

Limit & Position Switches

Micro Switches & Detector Switches

Push Button Switches & Components

Rocker Switches & Components

Rope Pull Switches & Components

Rotary Switches & Components

Safety Enabling & Control Switches

Safety Interlock Switches & Components

Switch Disconnectors & Components

Toggle Switches & Slide Switches

Electronic Components, Power & Connectors

Batteries & Chargers

Battery & Charger Accessories

Battery Chargers & Power Banks

Non-Rechargeable Batteries

Rechargeable Batteries

Connectors

AV Connectors

Automotive Electrical Connectors

Backplane & Rack Connectors

Circular Connectors

IC Sockets & Adapters

Mains & DC Power Connectors

Network & Telecom Connectors

PCB Connectors & Wire Housings

Power Connectors

RF Coaxial Connectors & Adapters

Terminal Blocks

USB, D Sub & Computing Connectors

Wire Terminals & Splices

Displays & Optoelectronics

Display Modules

Fibre Optic Components

Indicators & Indicator Components

LED Lighting Components

LEDs - Light Emitting Diodes

Laser Modules & Components

Optocouplers & Photodetectors

ESD Control, Cleanroom & PCB Prototyping

ESD Control & Clean Room

PCB Etching, Preparation & Developing

PCB Handling

PCB Spacers, Pillars & Supports

PCB Tools

Prototyping Boards

Passive Components

Antennas

Capacitors

Crystals, Oscillators & Resonators

EMI Filters & Protection

Fixed Resistors

Inductors

Passive Components Kits

Rotary Encoders

Sounder, Buzzer & Microphone Components

Surge Protection Components

Variable Resistors

Power Supplies & Transformers

Power Supplies

Renewable Energy

Transformers

Voltage Converters

Raspberry Pi, Arduino, ROCK, STEM Education & Development Tools

Arduino Shop

BBC micro:bit Shop

Development Tools & Single Board Computers

ROCK SBC Shop

Raspberry Pi Shop

STEM Education

Semiconductors

Amplifiers & Comparators

Audio & Video ICs

Chip Programmers & Debuggers

Clock, Timing & Frequency ICs

Communication & Wireless Module ICs

Data Converters

Discrete Semiconductors

Interface ICs

Logic ICs

Memory Chips

Power Management ICs

Processors & Microcontrollers

Programmable Logic ICs

Sensor ICs

Mechanical, Fluid Power & Tools

Access, Storage & Material Handling

Ladders & Steps

Material Lifting & Loading Equipment

Storage & Shelving

Transit & Equipment Cases

Trucks, Trolleys & Lifting Tables

Adhesives, Sealants & Tapes

Adhesive, Sealant & Tape Dispensers

Adhesives & Glues

Sealants & Resins

Tapes

Bearings & Seals

Gaskets, Seals & Packings

Linear Motion

Rotary Bearings & Housing Units

Engineering Materials & Industrial Hardware

Anti Vibration & Levelling Components

Carbon Fibre & Felt Sheets

Castors & Wheels

Ceramic Materials

Channel Support Systems

Conveyor Components

Insulation Materials

Knobs, Levers & Handles

Metal Materials

Plastic & Rubber Materials

Polishing & Finishing

Shim Stock

Structural Systems

Fasteners & Fixings

Clips & Springs

Girder Fixings

Magnets & Magnetic Strips

Nails & Rivets

Nuts & Washers

Pins, Keys & Retaining Clips

Screws & Bolts

Sheet Metal & Panel Fasteners

Spacers & Standoffs

Wall Plugs, Fixings & Anchors

Hand Tools

Cable, Connector & Crimping Tools

Clamps & Vices

Hammers & Demolition

Spirax Sarco Check Valves

6 Products showing for Spirax Sarco Check Valves

Popular Searches

Related links