TPZ / D-AP / D-AMP Automatic Valve w/ Pressure Override
The Chalwyn TPZ Bendix type automatic valve and D-AP Spindle type automatic valves are designed to automatically stop an engine by closing down the air intake in the event of an engine runaway or overspeed condition. These valves include a pressure override mechanism that will close the valve when supplied with an air pressure signal from the engine control system.
A remote cable actuated manual override to close the valve can be added to the TPZ valves and are included with the D-AMP valves. In addition an optional integral air filter can be mounted directly on the smaller sized TPZ valves to reduce the size and complexity of installing the valve into engine packages where space is limited. This eliminates the requirement to find a location to support and mount a separate air filter and the associated air intake line upstream of the valve.
Available models:
| Automatic/Pneumatic Override Valve Range |
Engine Power | Air Intake Hose Size | ||
|---|---|---|---|---|
| kW | HP | mm | in | |
| TPZ w/ Air Filter (Bendix type) | 7.5 – 93 | 10 – 125 | 51 – 96 | 2 – 3¾ |
| TPZ (Bendix type) | 7.5 – 179 | 10 – 240 | 51 – 108 | 2 – 4¼ |
| D‑AP (Spindle type) | 80 – 600 | 107 – 805 | 76 – 229 | 3 – 9 |
| Automatic/Pneumatic Override Valve Range w/ Manual Cable Stop |
Engine Power | Air Intake Line | ||
| kW | HP | mm | in | |
| TPZ w/ Air Filter (Bendix type) | 7.5 – 93 | 10 – 125 | 51 – 96 | 2 – 3¾ |
| TPZ (Bendix type) | 7.5 – 179 | 10 – 240 | 51 – 108 | 2 – 4¼ |
| D‑AMP (Spindle type) | 80 – 600 | 107 – 805 | 76 – 229 | 3 – 9 |
Features and Benefits
- Easy to install
- Automatic air flow actuated closure on overspeed
- Automatic reset after engine stops
- Pneumatic pressure to close override
- Remote manually operated cable close available
- Integral air filter available for smaller TPZ sizes
- Trip setpoint calibrated on engine
| Automatic/Pneumatic Override (with or without Manual Cable Stop) |
Engine Power |
Air Intake Hose Size |
||||||
| kW | HP | mm | in | |||||
| TPZ w/ Air Filter (Bendix type) | 7.5 - 93 | 10 - 125 | 51 - 96 | 2 - 3¾ | ||||
| TPZ (Bendix type) | 7.5 - 179 | 10 - 240 | 51 - 108 | 2 - 4¼ | ||||
| D-AP and D-AMP (Spindle type) | 80 - 600 | 107 - 805 | 76 - 229 | 3 - 9 | ||||
| Pressure to Close Override |
Minimum | Maximum | ||||||
| TPZ Air or Oil Pressure | 1.5 bar | 22 psi | 10 bar | 145 psi | ||||
| D-AM / D-AMP Air Pressure | 2.5 bar | 36 psi | 8 bar | 116 psi | ||||
| D200-AM / D200-AMP Air Pressure | 4 bar | 60 psi | 8 bar | 116 psi | ||||
- Drilling rigs (onshore & offshore)
- Drilling support equipment
- Well servicing equipment
- Refinery support equipment
- Bulk haulers and tankers
- Mining equipment
- Construction equipment
- Generator sets
- Emergency response vehicles and equipment
- Aircraft refueling equipment
- Work boats
- Barges
- Agriculture equipment
The Chalwyn TPZ Bendix and D-AP Spindle type automatic valves are designed to automatically stop an engine by closing down the air intake in the event of an engine runaway or overspeed condition. The valves are self-contained with flow actuated overspeed shutdown. They require no external electrical or mechanical input devices for the overspeed shutdown. The closing force is provided by the intake air flow passing through the valve. The valve closes automatically when the engine speed exceeds a pre-set point. The valve automatically resets open soon after the engine has stopped, so the engine is ready for re-starting. The valve trip set point is calibrated on engine after the valve has been installed.
Pressure to Close Override
These valves include a pressure override input that will close the valve when supplied with a pressure signal from the engine control system.
| Valve Type | Override Actuator | Pressure Signal | ||
|---|---|---|---|---|
| Medium | Minimum | Maximum | ||
| TPZ | Cylinder | Air or Oil | 1.5 bar (22 psi) | 10 bar (145 psi) |
| D‑AP / ‑AMP | Rotary | Air | 2.5 bar (36 psi) | 8 bar (116 psi) |
| D200‑AP / ‑AMP | Rotary | Air | 4 bar (60 psi) | 8 bar (116 psi) |
Remote Cable Operated Manual Close
A remote cable actuated manual override to close the valve can be added to the TPZ valves and are included with the D‑AMP valves.
| Valve Type | Manual Operator | Cable Lengths |
|---|---|---|
| TPZ | Pull “T” Handle | 1.0, 1.5, 2.0, & 3.0 meters |
| D‑AMP | Pull “T” Handle | 1.0, 1.5, 2.0, & 3.0 meters |
| D200‑AMP (only) | Shutdown Lever | 1.0, 1.5, 2.0, & 3.0 meters |
TPZ Valve Integral Air Filter
In addition an optional integral air filter can be mounted directly on the smaller sized TPZ valves to reduce the size and complexity of installing the valve into engine packages where space is limited. This eliminates the requirement to find a location to support and mount a separate air filter and the associated air intake line upstream of the valve.






