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T. Sundararajan et al.
to house the screw, which is used to adjust the spring tension. It has an opening
on one end which faces the pressurized tire.
(b) Nut (depicted as red line in Fig. 2)
The nut is used for tightening the PRV in the wheel rim, with a torque equal to
15–20 KN. The nut may be hexagonally indexed for easing spanner accessibility.
The nut has a hole in the top to facilitate the exhaust of air through the same.
The excess air pressure escapes through the hole in the body of the PRV and
escapes though the hole in the nut toward the atmosphere.
(c) Core (depicted as shaded gray-blue in Fig. 2)
The core of the PRV is the only moving component of the valve. One end of the
core has a plunger, in which sealant ring will be present. In this case, the sealant
ring is made out of silicone to withstand high temperature. The plunger seals
the valve on the inside, i.e., the valve end which is exposed to the tire pressure.
The other end of the core contains the seating of the spring.
(d) Spring (depicted as pink spiral lines in Fig. 2)
The spring is located in-between the screw and the core. The spring provides
the necessary tension to keep the core in position, and to push the core back
after pressure drop. The spring in this PRV is made out of stainless steel, due to
its excellent anti-corrosion properties.
(e) Screw (depicted as green line in Fig. 2)
The screw is located in the body of the PRV, in the topmost portion. The body
of the PRV has internal threads in it, in which the screw rotates. The primary
function of the screw is to adjust the spring tension, which determines the
opening pressure of the PRV.
(f) Sealant ring (depicted as shaded black in Fig. 2)
The sealant ring made of silicone is located in the bottom side of the core.
It firmly closes the opening of the PRV under spring tension during static
conditions and when it re-establishes contact.
(g) ‘O’ ring (depicted as solid black in Fig. 2)
The ‘O’ ring is used to prevent any air leak in fitment. This is similar to the
function of an ‘O’ ring in any inflation valve.
5.3 Problem and Solution
5.3.1 Higher Area of Exposure in the Core Post Opening of PRV
Apparently, the core of the PRV exposes a higher area toward the tire after the PRV
opens up. This is depicted in the picture and explanation below:
Figure 3 depicts a zoomed view of Fig. 2 in the opening region of the valve. The
thick red line marks the total area exposed to the tire pressure prior to the opening
of the valve. Let the area be A 1 . When the tire pressure acts on this area, it produces
a force F p1 on the core, which in turn causes a force F p1 to act on the spring. When
T. Sundararajan et al.
to house the screw, which is used to adjust the spring tension. It has an opening
on one end which faces the pressurized tire.
(b) Nut (depicted as red line in Fig. 2)
The nut is used for tightening the PRV in the wheel rim, with a torque equal to
15–20 KN. The nut may be hexagonally indexed for easing spanner accessibility.
The nut has a hole in the top to facilitate the exhaust of air through the same.
The excess air pressure escapes through the hole in the body of the PRV and
escapes though the hole in the nut toward the atmosphere.
(c) Core (depicted as shaded gray-blue in Fig. 2)
The core of the PRV is the only moving component of the valve. One end of the
core has a plunger, in which sealant ring will be present. In this case, the sealant
ring is made out of silicone to withstand high temperature. The plunger seals
the valve on the inside, i.e., the valve end which is exposed to the tire pressure.
The other end of the core contains the seating of the spring.
(d) Spring (depicted as pink spiral lines in Fig. 2)
The spring is located in-between the screw and the core. The spring provides
the necessary tension to keep the core in position, and to push the core back
after pressure drop. The spring in this PRV is made out of stainless steel, due to
its excellent anti-corrosion properties.
(e) Screw (depicted as green line in Fig. 2)
The screw is located in the body of the PRV, in the topmost portion. The body
of the PRV has internal threads in it, in which the screw rotates. The primary
function of the screw is to adjust the spring tension, which determines the
opening pressure of the PRV.
(f) Sealant ring (depicted as shaded black in Fig. 2)
The sealant ring made of silicone is located in the bottom side of the core.
It firmly closes the opening of the PRV under spring tension during static
conditions and when it re-establishes contact.
(g) ‘O’ ring (depicted as solid black in Fig. 2)
The ‘O’ ring is used to prevent any air leak in fitment. This is similar to the
function of an ‘O’ ring in any inflation valve.
5.3 Problem and Solution
5.3.1 Higher Area of Exposure in the Core Post Opening of PRV
Apparently, the core of the PRV exposes a higher area toward the tire after the PRV
opens up. This is depicted in the picture and explanation below:
Figure 3 depicts a zoomed view of Fig. 2 in the opening region of the valve. The
thick red line marks the total area exposed to the tire pressure prior to the opening
of the valve. Let the area be A 1 . When the tire pressure acts on this area, it produces
a force F p1 on the core, which in turn causes a force F p1 to act on the spring. When