Rubber back-up ring is STU support ring, Commonly used in hydraulic systems, especially hydraulic valves and pumps, but also to seal the bottom of the cylinder and the cylinder head (used with an O-ring). However, STU support rings are also used in many other areas throughout the industry, such as for sealing ball valves.The concave section of the supporting ring provides a larger contact surface for the O-ring, which has the effect of keeping the O-ring almost completely round under high pressure and resistant to deformation. This means that the shape of the O-ring is better supported and therefore can withstand higher pressure loads. This can produce better sealing effect and extend the service life of the seal. Because of its enclosed design, the O-ring cannot be damaged by the sharp edge at the open joint under high pressure (the same is true for the open support ring).
| 线径 W | 沟槽尺寸 groove dimension | 倒角③ r1 | 径向间隙 Smax | ||||
| 沟槽深度 Groove Depth① | 沟槽宽度 Groove width | ||||||
| 动密封 rotary seal |
静密封 static seal |
b1/b2 +0.2 | b2 +0.2 | b3 +0.2 | |||
| t1+0.05 | t/h +0.05 | ||||||
| 1.02 | 0.80 | 0.75 | 1.20 | ② | 0.10 | 0.03 | |
| 1.27 | 1.00 | 0.90 | 1.40 | 0.10 | 0.03 | ||
| 1.52 | 1.25 | 1.15 | 1.70 | 0.22 | 0.04 | ||
| 1.78 | 1.50 | 1.40 | 2.00 | 0.22 | 0.05 | ||
| 2.62 | 2.30 | 2.25 | 3.00 | 0.30 | 0.08 | ||
| 3.53 | 3.20 | 3.10 | 4.00 | 0.40 | 0.08 | ||
| 5.33 | 4.90 | 4.75 | 6.00 | 0.40 | 0.10 | ||
| 7.00 | 6.40 | 6.20 | 8.00 | 0.60 | 0.10 | ||
①O-ring grooves are also commonly used. In dynamic applications, friction may be greater and a stop ring must be installed
②When using the retainer, the groove should increase the corresponding thickness of the retainer.
③If the retaining ring is used, it is recommended that the radius r1 should always be designed by 0.25±0.2MM
①通常也可以使用O型圈沟槽。动态应用时，摩擦力可能更大，必须安装挡圈。
②使用挡圈时，沟槽应增加挡圈相应厚度。
③如果使用挡圈，建议半径r1应始终按0.25±0.2MM 设计。
