GROCO builds the bronze seacocks, valves, and fittings that control water below the waterline. Match the material, size, and thread to your through-hull and do it to ABYC standards. Anything that lets water in or out below the waterline has to be done right, and GROCO has built marine seacocks, valves, and through-hull fittings to that standard for generations. This collection covers flanged seacocks, ball valves, thru-hull fittings, flange adapters, check valves, and the bronze and stainless plumbing parts a safe install needs. The keys are material, correct sizing and thread, and a seacock you can actually reach and operate. Use a real seacock below the waterline A seacock is a valve bolted to the hull that you can shut...
Bronze Pipe Nipple - 2-1/2" NPT Features: Cast-in wrench flat simplifies installation and removal NPT x NPT Connection C83600 Bronze Full flow Note-C83600 bronze fittings are not...
Bronze Pipe Nipple - 1/2" NPT Features: Cast-in wrench flat simplifies installation and removal NPT x NPT Connection C83600 Bronze Full flow Note-C83600 bronze fittings are not...
3" Full Flow Ball ValveThis GROCO flanged ball valve is designed for controlling the flow and pressure of fluids in a pipeline system.Features: 1-1/4" sizes and larger include...
4" Bronze Flanged Seacock & Adaptor with 3" NPT Side PortFeatures: Two driver ports permit handle relocation NPT threaded side port accepts SSCV or any NPT threaded accessory...
3" Safety Seacock w/2-1/2" Side Port Features: Two driver ports permit handle relocation. NPT threaded side port accepts SSCV or any NPT threaded accessory. Handle has square hole that...
2-1/2" Safety Seacock w/2" Side Port Features: Two driver ports permit handle relocation. NPT threaded side port accepts SSCV or any NPT threaded accessory. Handle has square hole that...
2" Safety Seacock w/1-1/2" Side Port Features: Two driver ports permit handle relocation. NPT threaded side port accepts SSCV or any NPT threaded accessory. Handle has square hole that...
1-1/2" Safety Seacock w/1-1/4" Side Port Features: Two driver ports permit handle relocation. NPT threaded side port accepts SSCV or any NPT threaded accessory. Handle has square hole that...
1-1/4" Safety Seacock w/1" Side Port Features: Two driver ports permit handle relocation. NPT threaded side port accepts SSCV or any NPT threaded accessory. Handle has square hole that...
1/2" 4-Port Tank Selector ValveFeatures: For fuel or water Four Positions: Tank-1, Tank-2, Tanks 1 & 2, Off Full 1/2” flow Audible “click” at each handle position For...
1/2" NPT 90° Stainless Steel Fuel ValveFeatures: Compact design 90° flow path 1/2" NPT male and female ports Use FV-590 (Brass) for fiberglass tanks Use FV-590-S (316SS) with...
3/4" NPT Bronze Inline Fuel ValveFeatures: Selectable handle rotation Full flow Mount foot included C83600 bronze construction Stainless steel handle and hardware 400 WOG PTFE seats and seals...
2" Bronze In-Line Check ValveFeatures: C83600 cast bronze construction NPT threaded ports 1/2" - 2" sizes Suitable for use with diesel fuel or gasoline SurTrack produces new CV...
1-1/2" Bronze In-Line Check ValveFeatures: C83600 cast bronze construction NPT threaded ports 1/2" - 2" sizes Suitable for use with diesel fuel or gasoline Groco 1-1 / 2...
1-1/4" Bronze In-Line Check ValveFeatures: C83600 cast bronze construction NPT threaded ports 1/2" - 2" sizes Suitable for use with diesel fuel or gasoline The Groco 1-1/4 copper...
1/2" Bronze In-Line Check ValveFeatures: C83600 cast bronze construction NPT threaded ports 1/2" - 2" sizes Suitable for use with diesel fuel or gasoline The Groco 1/2 bronze...
Perforated Hull Strainer with Access Door 2" Max Thru-HullFeatures: Access door design allows easy access to Thru Hulls C84400 bronze body and door Cast filter slots Pressure relief...
Perforated Hull Strainer with Access Door 1-1/4" Max Thru-HullFeatures: Access door design allows easy access to Thru Hulls C84400 bronze body and door Cast filter slots Pressure relief...
1-1/2" Inlet Hydromatic Self-Cleaning Strainer - 12VFeatures: 30-second cleaning cycle is automatically performed at user-selected intervals Optional interface with SSA system ( initiates cleaning cycle when flow is...
3" Bronze Electric Flanged Seacock - 24VFeatures: Motorized (12V or 24V) valve operation for seacock sizes 3/4" to 3" (4" and 5" available soon) Manual valve operation if...
3" Bronze Electric Flanged Seacock - 12VFeatures: Motorized (12V or 24V) valve operation for seacock sizes 3/4" to 3" (4" and 5" available soon) Manual valve operation if...
2-1/2" Bronze Electric Flanged Seacock - 24VFeatures: Motorized (12V or 24V) valve operation for seacock sizes 3/4" to 3" (4" and 5" available soon) Manual valve operation if...
2-1/2" Bronze Electric Flanged Seacock - 12VFeatures: Motorized (12V or 24V) valve operation for seacock sizes 3/4" to 3" (4" and 5" available soon) Manual valve operation if...
2" Bronze Electric Flanged Seacock - 24VFeatures: Motorized (12V or 24V) valve operation for seacock sizes 3/4" to 3" (4" and 5" available soon) Manual valve operation if...
GROCO builds the bronze seacocks, valves, and fittings that control water below the waterline. Match the material, size, and thread to your through-hull and do it to ABYC standards.
Anything that lets water in or out below the waterline has to be done right, and GROCO has built marine seacocks, valves, and through-hull fittings to that standard for generations. This collection covers flanged seacocks, ball valves, thru-hull fittings, flange adapters, check valves, and the bronze and stainless plumbing parts a safe install needs. The keys are material, correct sizing and thread, and a seacock you can actually reach and operate.
A seacock is a valve bolted to the hull that you can shut to stop the flow through a through-hull, and it is what stands between your boat and a sinking if a hose fails. GROCO flanged seacocks mount to a backing and take the load off the through-hull itself. Do not substitute a cheap gate valve or a bare ball valve threaded onto a through-hull for a below-waterline application.
GROCO bronze is the traditional choice below the waterline, strong and proven, and it must be bonded to the boat's system to control corrosion. Stainless is common for above-waterline and adapter fittings but is not ideal for a submerged valve body. Match the material to the location and keep dissimilar metals in mind to avoid galvanic trouble.
Fittings are sized by pipe thread, and marine plumbing mixes NPS straight and NPT tapered threads. GROCO offers flange adapters to mate NPS through-hulls to NPT valves correctly, which is exactly where people get into trouble forcing mismatched threads. Match the size and thread type, and use the right adapter rather than overtightening a bad fit.
Check valves keep water flowing one way, which protects pumps and prevents back-siphoning. Raw-water strainers on the intake keep debris out of your engine cooling and pumps. Size these to the hose and flow so they do not choke the system.
A seacock you cannot reach is a seacock you will not close in an emergency. Mount valves where you can operate them by hand, and exercise them regularly so they do not seize. Replace any valve that is stiff, corroded, or weeping.
Not sure which GROCO parts your plumbing needs? Tell our techs the through-hull size, location, and thread, and we will match the seacock, valve, adapters, and strainer so the system is safe and seals tight. Always confirm thread types before ordering to prevent leaks at the hull. Regular inspection of all below-waterline fittings helps catch corrosion early and keeps your boat safe on the water.
A seacock is a valve designed and mounted to take the load off the through-hull and let you shut the flow if a hose fails. Below the waterline, that is what stands between your boat and sinking. Do not substitute a gate valve or a bare ball valve threaded onto a through-hull.
Bronze is the traditional and proven choice for submerged valve bodies and must be bonded to control corrosion. Stainless suits above-waterline and adapter fittings but is not ideal for a submerged valve. Match the material to the location.
NPS is straight thread and NPT is tapered. Marine plumbing mixes both, and forcing them together leaks or cracks. GROCO flange adapters mate NPS through-hulls to NPT valves correctly, so use the right adapter instead of overtightening a mismatch.
A strainer on the intake keeps debris out of your engine cooling and pumps, which prevents clogs and overheating. Size it to the hose and flow so it does not choke the system, and clean it regularly.
Mount them where you can reach and operate them by hand, exercise them regularly so they do not seize, and replace any valve that is stiff, corroded, or weeping. A seacock you cannot close in an emergency is a real hazard.
