Vetus Waterlock NLP Installation Manual

Introduction

The VETUS exhaust system components are specifically designed for water-injected exhaust systems. The maximum continuous operating temperature is dependent on the material used in the waterlock construction, which can be identified by its color.

It is recommended to fit a temperature alarm to signal excessively high exhaust system temperatures. If the quantity of injected coolant water is reduced to lower back-pressure, ensure sufficient water is injected during engine idling to prevent overheating. Poor mixing of coolant water and exhaust gases can also lead to high temperatures. Optimal mixing is generally achieved with a nearly vertical exhaust injection bend. Poor mixing can occur with engines idling, especially if the coolant water injection bend is nearly horizontal. Consider installing a water vortex or water splitter in the exhaust pipe to improve mixing.

Use a high-quality hose for water-injected exhaust systems. The hose must be reinforced, resistant to exhaust gases, high temperatures (100°C / 212°F), and oil. It should be flexible for installation and not collapse when heated. VETUS exhaust hoses meet these requirements.

* Based on an allowed back pressure of 0.1 bar.

Installation

2.1 Installing Waterlock NLP

Install the waterlock as vertically as possible. If space behind the engine is limited, position the waterlock 'back-to-front' alongside the engine. Due to water accumulation during use, the waterlock's weight increases significantly. Mount it securely on the deck or a wall.

NOTE: Ensure the following conditions are met under all sailing conditions (e.g., heeling):

• The waterlock 'IN' connection must be below the level of the exhaust injection bend.
• The distance between the bottom of the engine's cooling water outlet and the highest point of the waterlock must be at least 5 cm (2 inches).

For additional exhaust system information, refer to Chapter 3.

2.2 Installing the Transom Exhaust Connection

Fit the transom exhaust connection so that the outlet remains at least 5 cm (2 inches) above the waterline when the ship is fully laden.

2.3 Exhaust Pipe

To ensure proper drainage of coolant water injected into the exhaust pipe, the pipe must be installed with a downward slope along its entire length, from the water injection point to the waterlock. The exhaust pipe contains water during operation, increasing its weight; therefore, support the exhaust pipe properly. The exhaust pipe from the waterlock to the transom connection must be installed such that:

• The highest point in the exhaust pipe is not more than 150 cm (60 inches) above the underside of the waterlock.
• The length of the section between the waterlock and the highest point does not exceed 300 cm (120 inches).

2.4 Hose Connections

To achieve optimal connection of hoses to the waterlock, both hose connections can rotate 360°. Loosen the bolts before turning the hose connections. Tighten the hose connections to a torque of 1 Nm (0.75 ft.lb).

2.5 Fitting the Hose

To ease hose fitting, use only water and/or soap, not grease or oil-based products. Fit each hose connection with two stainless steel hose clamps, 12 mm (0.5 inches) wide.

2.6 Sensor for Temperature Alarm

A sensor for a temperature alarm can be fitted in the exhaust pipe.

Installation Examples

Page 18 shows exhaust systems with a waterlock (NLP type), silencer (MP type), gooseneck (NLPG type), and transom connection. The extra height difference in the gooseneck virtually prevents water entry from the stern. When the engine stops, any water remaining in the exhaust pipe will run back to the silencer. To minimize this water, the gooseneck should be fitted directly above the silencer if possible (see drawings 1 and 3). If the gooseneck is fitted directly to the transom (drawings 2 and 4), consider the maximum length of the exhaust pipe between the silencer and the highest point.

3.1 Prevention of Syphoning (drawings 3 & 4)

If the water injection point 'C' is below or less than 15 cm (0.6 inches) above the waterline (even when the ship heels), there is a risk of coolant water entering the engine due to syphoning when the engine is stopped. Syphoning can be prevented in two ways:

• By creating an air vent system in the coolant water hose between the engine block and point 'C', for example, by fitting an air vent with a vent pipe. The vent pipe can connect to its own hull outlet (H) or to the designated connection on the gooseneck (NLPG type, G). Refer to the NLPG manual (No. 030428.0x).
• By fitting an air vent (with valve) in the coolant water hose between the engine block and point 'C'.

Maintenance

Regularly check all hose connections for gas and water leaks. Before winter lay-up, drain the waterlock. The waterlock has two drain plugs for this purpose.

Diagrams

Diagrams illustrating hose connections and installation examples are provided throughout the manual.

Diagrams of Hose Connections

The hose connections for NLP40/45/50 and NLP50S/60/65/75/90 models are shown, indicating their 360° rotatable nature for optimal hose alignment.

Installation Examples

Figures 1 through 4 illustrate various exhaust system configurations with the Waterlock NLP, including the use of silencers, goosenecks, and transom connections. Specific details are provided for systems where the water injection point 'C' is above or below the waterline, and methods for preventing syphoning are detailed.

Dimensions

Principal Dimensions

Detailed dimensions are provided for the NLP40, NLP45, NLP50 models and the NLP50S, NLP60, NLP65, NLP75, NLP90 models, including volume specifications.

Rubber Exhaust Hose

A table lists the specifications for rubber exhaust hoses, including Inner Diameter (I.D.), Outer Diameter (O.D.), and minimum bending radius (R min.).

Warnings

WARNING: If water enters the engine from the waterlock into the exhaust system (e.g., during heavy seas), it can cause irreparable damage to the engine. Excessive water in the waterlock can impede engine starting; drain the waterlock first. This can also be caused by repeated unsuccessful starting attempts.

CAUTION: Ensure all conditions are met under all sailing conditions, including heeling.