NOK Type Hydraulic Piston Seal SPG
SPG is a compact double acting piston seal for medium to heavy duty applications. The reinforced, heat stabilized, thermoplastic sealing face with step-cut joint allows the seal to pass over ports, making it an ideal choice for double acting telescopic cylinders.
It comprises a bronze filled PTFE face ring, which is pre-loaded by a square section NBR ring. The cap ring is precision machined from a compression moulded billet. Compression moulding of the material offers consistently superior physical properties as compared to automatic moulded products. The machined face ring has chamfered corners for easy installation and a surface finish free from the “orange peel” effect associated with automatic moulded products. As only the PTFE face ring is in contact with the sliding surface, friction is very low and stick slip movement is eliminated. The housing width allows the designer to use a narrow width piston, but it is recommended that an adequate bearing be mounted on either side of the seal as shown.
Materials
Standard materials are bronze / PTFE with a NBR square section energizer.

Material | Poer-transmission fluid | Temperature | Speed | Pressure | Max. Gap F |
PTFE+bronze | Mineral Oil (NBR) | -30 – +110 | ≦ 15m/s | 160 bar | F ≦ 0.6mm |
Mineral Oil (FKM) | -30 – +200 | 250 bar | F ≦ 0.4mm | ||
400 bar | F ≦ 0.2mm |
Chamfers & Rad(mm) | Tolerance | Surface Finishing | ||||||||
μm Ra | μm Rt | |||||||||
S ≦ | 3.75 | 5.5 | 7.5 | 10.5 | 12.5 | 15 | ØD1 | H9 | 0.1-0.4 | ≦ 4 |
C ≧ | 2 | 3 | 5 | 7.5 | 8 | 8.5 | Ød1 | h9 | ≦ 1.6 | ≦ 10 |
r1 ≧ | 0.4 | 0.8 | 1.2 | 1.6 | 1.6 | 2.0 | L | +0.2 – 0 | ≦ 3.2 | ≦ 16 |
SPG PISTON SEAL LIST
ITEM NO. | SIZE | ||||
SPG | d | D | h | H | C |
30 | 20.5 | 30 | 4.3 | 4.5 | 2 |
31.5 | 22 | 31.5 | 4.3 | 4.5 | 3.5 |
32 | 22.5 | 32 | 4.3 | 4.5 | 3.5 |
35 | 25.5 | 35 | 4.3 | 4.5 | 3.5 |
35.5 | 26 | 35.5 | 4.3 | 4.5 | 3.5 |
40 | 30 | 40 | 4.3 | 4.5 | 3.5 |
45 | 35 | 45 | 4.3 | 4.5 | 3.5 |
50 | 40 | 50 | 4.3 | 4.5 | 4 |
55 | 45 | 55 | 4.3 | 4.5 | 4 |
56 | 46 | 56 | 4.3 | 4.5 | 4 |
60 | 50 | 60 | 4.3 | 4.5 | 4 |
63 | 48 | 63 | 7.3 | 7.5 | 4 |
65 | 50 | 65 | 7.3 | 7.5 | 4 |
69 | 54 | 69 | 7.3 | 7.5 | 4 |
70 | 55 | 70 | 7.3 | 7.5 | 5 |
71 | 56 | 71 | 7.3 | 7.5 | 5 |
75 | 60 | 75 | 7.3 | 7.5 | 5 |
80 | 65 | 80 | 7.3 | 7.5 | 5 |
85 | 70 | 85 | 7.3 | 7.5 | 5 |
90 | 75 | 90 | 7.3 | 7.5 | 5 |
95 | 80 | 95 | 7.3 | 7.5 | 5 |
100 | 85 | 100 | 7.3 | 7.5 | 5 |
105 | 90 | 105 | 7.3 | 7.5 | 5 |
108 | 92 | 108 | 7.3 | 7.5 | 5 |
110 | 94 | 110 | 7.3 | 7.5 | 5 |
112 | 96 | 112 | 7.3 | 7.5 | 6.5 |
120 | 104 | 120 | 7.3 | 7.5 | 6.5 |
125 | 109 | 125 | 7.3 | 7.5 | 6.5 |
130 | 114 | 130 | 7.3 | 7.5 | 6.5 |
135 | 119 | 135 | 7.3 | 7.5 | 6.5 |
140 | 124 | 140 | 7.3 | 7.5 | 6.5 |
145 | 129 | 145 | 7.3 | 7.5 | 6.5 |
150 | 134 | 150 | 7.3 | 7.5 | 6.5 |
155 | 139 | 155 | 7.3 | 7.5 | 6.5 |
160 | 144 | 160 | 7.3 | 7.5 | 6.5 |
170 | 148 | 170 | 10.8 | 11 | 6.5 |
180 | 158 | 180 | 10.8 | 11 | 6.5 |
190 | 168 | 190 | 10.8 | 11 | 6.5 |
200 | 178 | 200 | 10.8 | 11 | 6.5 |
204 | 182 | 204 | 10.8 | 11 | 6.5 |
210 | 188 | 210 | 10.8 | 11 | 6.5 |
215 | 193 | 215 | 10.8 | 11 | 6.5 |
220 | 198 | 220 | 10.8 | 11 | 6.5 |
224 | 202 | 224 | 10.8 | 11 | 6.5 |
225 | 203 | 225 | 10.8 | 11 | 6.5 |
ITEM NO. | SIZE | ||||
SPG | d | D | h | H | C |
230 | 208 | 230 | 10.8 | 11 | 6.5 |
240 | 218 | 240 | 10.8 | 11 | 6.5 |
250 | 228 | 250 | 10.8 | 11 | 6.5 |
260 | 236 | 260 | 11.7 | 12 | 7.5 |
270 | 246 | 270 | 11.7 | 12 | 7.5 |
280 | 256 | 280 | 11.7 | 12 | 7.5 |
290 | 266 | 290 | 11.7 | 12 | 7.5 |
300 | 276 | 300 | 11.7 | 12 | 7.5 |
310 | 286 | 310 | 11.7 | 12 | 7.5 |
320 | 296 | 320 | 11.7 | 12 | 7.5 |
330 | 308 | 330 | 9.75 | 10 | 10 |
360 | 336 | 360 | 11.7 | 12 | 10 |
400 | 376 | 400 | 11.7 | 12 | 10 |
485 | 455 | 485 | 14.8 | 15 | 10 |
500 | 470 | 500 | 14.8 | 15 | 10 |
550 | 515 | 550 | 17.2 | 17.5 | 10 |
600 | 570 | 600 | 14.8 | 15 | 10 |
650 | 620 | 650 | 14.8 | 15 | 15 |
720 | 690 | 720 | 14.8 | 15 | 15 |
800 | 785 | 800 | 12.7 | 13 | 15 |
900 | 870 | 900 | 24.5 | 25 | 15 |
930 | 890 | 930 | 19 | 20 | 15 |
935 | 920 | 935 | 12.7 | 13 | 15 |
950 | 925 | 950 | 17.7 | 18 | 15 |
1000 | 960 | 1000 | 19.7 | 20 | 20 |
1060 | 1020 | 1060 | 19.7 | 20 | 20 |
1120 | 1080 | 1120 | 19.7 | 20 | 20 |
1150 | 1110 | 1150 | 19.7 | 20 | 20 |
1180 | 1130 | 1180 | 19.7 | 20 | 20 |
1210 | 1170 | 1210 | 19 | 20 | 20 |
1250 | 1210 | 1250 | 19.7 | 20 | 20 |
1260 | 1220 | 1260 | 19.7 | 20 | 20 |
1400 | 1350 | 1400 | 19.7 | 20 | 20 |
1500 | 1460 | 1500 | 19.7 | 20 | 20 |
1650 | 1600 | 1650 | 24 | 25 | 20 |