Tractor protection valve – SGI
When the trailer-supply valve is open, air passes through the bottom of the valve and charges the trailer, while spring pressure closes the service line port to protect the application air pressure in the truck.
How is the tractor protection valve operation?
When the trailer-supply valve is open, air passes through the bottom of the tractor protection valve and charges the trailer through the supply line (also known as the emergency line), and the tractor protection valve’s service line port opens when the pressure in the supply line reaches 45 psi.
What’s the purpose of a tractor protection valve?
The tractor protection valve keeps air in the tractor or truck brake system if the trailer breaks away or develops a leak in a combination vehicle with air brakes.
What happens when the tractor protection valve closes?
When the tractor protection valve closes, it prevents any air from leaving the tractor and lets air out of the trailer emergency line, causing the trailer emergency brakes to engage, potentially resulting in a loss of control. (Emergency brakes will be discussed later.)
What is another name for the tractor protection valve?
Any truck designed to tow a trailer with air brakes will have a tractor protection system, which consists of the tractor protection valve–just to confuse you [CHCUCKLING], the system and the valve are the same thing–and the red, eight-sided trailer air supply valve.
What color is the tractor protection valve?
The TSV, also known as a ‘towing vehicle’ protection valve, is controlled by the driver and has a red colored, eight-sided knob. The driver opens (pushes in) the TSV when a trailer is being towed and closes it (pulls out) when no trailer is present.
Which shutoff valves should be open and closed?
If you’re only towing one trailer, the shut off valves should always be closed; if you’re towing multiple trailers, all valves should be open except the very last trailer, which should have all valves closed.
What is the blue air brake button for?
The yellow one controls all axle brakes, the red one only controls trailer brakes, and the blue one only controls the truck unit.
At what pressure must the tractor protection valve operate to pass inspection?
Breakaway and emergency braking are addressed in Title 49, Section 393.43, which establishes an “explicit requirement that the tractor protection valve or similar device operate when the air pressure u2013 both primary and secondary reservoirs u2013 on the towing vehicle is between [20 and 45 psi].”
What keeps the air in the tanks?
The one-way check valve keeps the air in the tank if the air compressor develops a leak. Air brakes take longer to activate than hydraulic brakes because air takes longer to flow through the lines.
What is the purpose of a tractor?
Tractors are agricultural machines that can be used to pull a variety of farm implements for plowing, planting, cultivating, fertilizing, and harvesting crops, as well as hauling materials and personal transportation.
What is the emergency air line for?
The emergency air line (also known as the supply line) serves two purposes: (1) to supply air to the trailer air tanks, and (2) to control the trailer emergency brakes on combination vehicles. When the emergency air line loses pressure, the trailer emergency brakes activate.
What position should the tractor protection valve?
The tractor protection valve is situated beneath the tractor’s frame, where the flexible airlines leading to the trailer are connected by glad hands coupling devices.
What is the blue air line on a tractor trailer?
The blue line is the air line for the trailer’s service brake; before moving the trailer, connect these lines to the corresponding couplers and sockets on the trailer; we recommend starting with the blue line because it is the furthest away.
What is a treadle valve?
The treadle valve has two circuits: a primary circuit and a secondary circuit, with the primary circuit’s delivery port connected to the relay valve’s control port and the relay valve’s delivery ports connected to the two rear brake chambers.