Pacific MotorYachts Ltd

We are running the engine room bilge, fuel and domestic plumbing systems. This is what we call “first fix” with all the systems installed and machinery bases and bracketing; final welding, completed before paint system application. 

The photo above shows the bilge and sea water pumps; main and standby. 

All hull openings; sea cocks, stern tubes and stabilizer actuator bases are contained in the engine room. All overboard discharges exit from the engine room. This allows ease of inspection of these openings.

We have always used metallic material for piping, either stainless steel or Copper Nichol for sea water piping and stainless for bilge system and fuel lines. In the case of fuel our primary concern is for protection in the event of fire. 

The use of metallic piping also helps in ensuring the integrity of watertight bulkheads in the event of any compartment flooding or fire; fire and stranding statistically being the two major causes of loss of vessel. This means all engine room piping is metallic. All fuel tanks are arranged to face the engine room so that there are no fuel lines outside the engine room space; avoiding any possibility of endangering accommodation areas. Bilge system piping is metallic throughout the vessel.

Domestic piping outside the engine room space is from ABS for waste pipes and Pexel™ or copper for domestic hot and cold water deliver.

This may seem excessive in both cost and caution, and there are those who may argue that modern plastics and rubber substitutes are quite adequate for many of these functions. We differ. The reality is maritime history is full of lessons in the care that must be taken in keeping a ship safe and it is not until the consequences of a fire are seen at first hand that the point is driven home.

When the vessels sea cocks are opened the inside of the vessel is being opened up to the sea. It is desirable that the piping carrying the sea water should be of such reliability and durability as the hull fabric. Where this integrity is broken, and there are points where it must be, extreme care needs to be taken.

Sea water, bilge and fuel lines are made up from pipe and fittings; elbow’s, tees and reducers. Here we use the TIG welding process that was originally developed for aircraft fabrication as an alternative to gas welding and is now universally used for pipe welding, especially where cleanliness is desirable.

The photo above shows a “root” weld being run. This is a “purge” weld process where the weldment is full depth or thickness and full strength of the material. In other words the inside of the pipe is welded as well as the outside.

The “tee” connection above shows a “root run” on the left and a second or “cap run”; the completed weld, on the right. 

All pipe work is “flange’ connected for easy removal at any time in the future.

The use of different pipe fittings allow for “cranky” sections. Here two 45degree and two 90degree elbows allow this fuel line to avoid structural and machinery parts while maintaining a neatness of installation.

Metallic piping is expensive to fabricate and install. The cost difference with plastics and rubber alternatives is huge. We know of no other builder who offers this level of integrity as a standard installation. However this cost amortized over the life of the vessel and considering its fire resistance and overall safety features works out very cost effective in the long run.

Owners of motor yachts, especially those cruising offshore, soon come to appreciate well laid out, robust, reliable systems and enjoy the lack of need for maintenance.