Best Merrill in 2026

No lead brass construction

1 in. x 1 in. female NPT

Prevents backflow in well or irrigation systems

Standard water well pump replacement switch designed for use of electrically driven water well pumps of all types (Jets, Submersible, Reciprocating etc)

Cut-In Pressure 40 PSI - Cut-Off Pressure 60 PSI - Adjustable

Large silver contacts for longer service life

Controls electrically driven water pumps

Cut-In Pressure 40 PSI - Cut-Off Pressure 60 PSI - Adjustable

Extra large silver contacts for longer service life

Pressure relief valves are for protection against excessive pressure

3/4 in. male NPT x 1/2 in. female FPT

Lead free brass with stainless steel control springs

Compatible with shallow well or drive point applications

No- Lead

Adjustable Cap for Handle Positions

Pressure relief valves are for protection against excessive pressure

1/2 in. male NPT x 1/2 in. female FPT

Lead free brass with stainless steel control springs

Pressure relief valves are for protection against excessive pressure

1/2 in. male NPT x 1/2 in. female FPT

Lead free brass with stainless steel control springs

Pressure relief valves are for protection against excessive pressure

Lead free brass with stainless steel control springs

3/4" Line Connection, 100 PSI

Standard water well pump replacement switch designed for use of electrically driven water well pumps of all types (Jets, Submersible, Reciprocating etc)

Cut-In Pressure 30 PSI - Cut-Off Pressure 50 PSI - Adjustable- Low Pressure Cut-Off - Manual Lever

Large silver contacts for longer service life

Water Pump Pressure Switch

Turns on at 40 psi and off at 60 psi

Individually boxed

Heavy duty cast iron body construction with internal pump cyclinder

Designed for shallow well applications (25' or less)

Antique Style - Molded rubber flapper & cup seal

G65 - Plunger bushing

G70 - Plunger body

G75 - Plunger bolt

1-1/2 slip x slip unions

Flapper bends over a radius to eliminate sharp 90-degree edges

Capable of vertical or horizontal installation

Bronze body construction ensures durability and long life

Designed for minimum head loss

The bonnet is made of engineered thermoplastic and protects valve body from costly freeze damage

For Oxygen Pumps Only: Great 1-way check valve for most common aquarium air pumps. NOT suitable for CO2 or other high-pressure systems to avoid crack and leak.

Small & Light: Size: 2.1" L x 0.55" W; Diameter of air holes: 0.12"; Weight: 0.1 oz. Standard ID airline tubing: 3/16". Add little weight to your hose for smooth airflow.

Ideal Pump Protectors: Prevent backflow of water through the tubing during a power outage or pump pause. Essential accessories for basic aeration setup in your fish tanks.

For Oxygen Pumps Only: Great 1-way check valve for most common aquarium air pumps. NOT suitable for CO2 or other high-pressure systems to avoid crack and leak.

Small & Light: Size: 2.1" L x 0.55" W; Diameter of air holes: 0.12"; Weight: 0.1 oz. Standard ID airline tubing: 3/16". Add little weight to your hose for smooth airflow.

Ideal Pump Protectors: Prevent backflow of water through the tubing during a power outage or pump pause. Essential accessories for basic aeration setup in your fish tanks.

No lead brass construction

1 in. x 1 in. female NPT

Prevents backflow in well or irrigation systems

Will fit any 1-1/4-inch or 1-1/2-inch NPT male or female thread

Made from durable ABS plastic

High quality Nitril-Bruna N seal

Material: Made of aluminum alloy check valve,304 stainless steel spring,NBR rubber gasket and O-ring.

Size: 1/4inch (6mm) OD check valve can be work with 1/4 inch ID fuel hose.

Parameter: Min upstream pressure:0.2bar(2.9psi),working pressure range: 0.2-6bar (2.9-87psi),operating temperature range: -22℉ to 266℉.

Can be used as a tank check valve for small compressors or as a component in pneumatic circuits

Brass for corrosion resistance, ductility at high temperatures, and low magnetic permeability

Fluorocarbon O-rings for higher temperature and chemical resistance

Schedule 40 PVC construction for strength and resistance to corrosion and mild chemicals

EPDM seal for resistance to water and oils

Maximum pressure rating of 150 psi

Upgraded stainless spring & pin make STRONGER spring tension

Improved chlorine-resistant and corrosion-resistant fabrication on flapper and rubber seal

Enhanced cover construction to be anti-crack and sturdy

Function: the check valves are applicable for fluid systems to prevent countercurrent liquids, or for pneumatic systems to prevent reverse flow of compressed air

Material and size: the one way check valves are made of PVDF, sturdy, wear-resistant and durable for long-term use; Each check valve measures 6.3 mm/ 1/4 inches, the total length is 38 mm/ 1.50 inches

Features: the pipe port of the check valve is designed with a pagoda-shaped card slot, non-slip and non-toxic, with good airtightness and good adsorption performance

Some GM Genuine Parts may have formerly appeared as ACDelco GM Original Equipment (OE)

GM Genuine Parts are designed, engineered and tested to rigorous standards, and are backed by General Motors

GM Engineers design and validate OE parts specifically for your Chevrolet, Buick, GMC, or Cadillac vehicle

Clear PVC for corrosion resistance, high strength, and less weight than fittings made from metal

Full flow design for insignificant flow loss at swing check

Slip connection for easy attachment

Material: this check valve is made of ABS plastic, and the internal valve core is made of silicone, ABS plastic has high hardness, good heat resistance and corrosion resistance, strong resistance to acids and alkalis, and is resistant to organic solvents to some extent

Suitable size: you will get 6 no-return check valves with a size of 3/8 inch, which is 1.61 inches long, enough quantity to meet your use of check valves in different situations to prevent fluid backflow

Function introduction: 3/8 check valve is applied in fluid system to prevent fluid backflow, or applied in pneumatic system to prevent compressed air backflow; This check valve can be applied in the temperature range of -20 degrees Celsius to 70 degrees Celsius

For Oxygen Pumps Only: Great 1-way check valves for most common aquarium air pumps. DO NOT use them in CO2 or other high-pressure systems to avoid cracking or leakage.

Small & Light: Size: 1.66" L x 0.5" W; Diameter of air holes: 0.12"; Weight: 0.07 oz. Standard ID airline tubing: 3/16". Add little weight to your hose for smooth airflow.

Ideal Pump Protectors: Effectively prevent water backflow during a power outage or pause of the pump. Ideally protect your pump and reduce your loss when you’re at work or on vacation.

Material ※ The shell material is ABS resin, and the Diaphragm material is silicon rubber

Performance※ Normal performance under 25 ℃ to 60 ℃,Strong resistance to acid, alkali, salt corrosion ability

Application ※Check valve is used in fluid system to prevent reverse flow fluid, or used in pneumatic system to prevent reverse flow of compressed air

Top-mounted test cocks allow for easy installation

EZSwap pressure vessel reduces repair time and costs

Flush Tool (FLUSH) provides easy line flushing, saving up to 15 minutes per installation