MATERIALS
The many possible operating conditions require different materials both for the sleeves and for the springs. The former are usually made of PTFE and/or PTFE modified according to the temperatures and pressures of the design; however other polymers are also available such as Peek®, Peek caricati, Vespel®, Kel-F® etc. for use in special situations.
The springs can be made of Inox 301, Inox304, Inox 316, 17-7PH, Hastelloy® C276, Inconel® 718 ed Elgioloy®. If these types are used or not depends on the type of seal – whether static or dynamic, if more or less friction is wanted to be created, the temperatures and the chemical compatibility with the contact fluid.
CHEMICAL COMPATIBILITY
** Chemical compatibility refers to contact with gas and hydrocarbons as described:
Use 1 = Gas and refi ned hydrocarbons
Use 2 = Unrefi ned hydrocarbons
Use 3 = hydrocarbons with Hydrochloric and Sulphuric acid
G = Suitable
S = Adequate
B = Not recommended
| Sleeve material | Chemical compatibility ** | Max. Temp. °C |
| PTFE Virgin | Type 1,2,3 – G | -220/+300°C |
| PTFE+Graphite | Type 1,2,3 – G | -220/+300°C |
| PTFE+Carbon-graphite | Type 1,2,3 – G | -220/+300°C |
| PTFE+Glass | Type 1,2,3 – G, Type 3-S | -220/+300°C |
| PTFE + Peek | Type 1,2,3 – G | -220/+300°C |
| TFM Virgin | Type 1,2,3 – G | -220/+300°C |
| TFM + Graphite | Type 1,2,3 – G | -220/+300°C |
| TFM + Carbon-graphite | Type 1,2,3 – G | -220/+300°C |
| TFM + Glass | Type 1,2,3 – G, Tipo 3-S | -220/+300°C |
| Peek® | Type 1,2,3 – G | -50/+320°C |
| Peek+Graphite | Type 1,2,3 – G | -50/+320°C |
| Vespel® | Type 1,2,3 – G | -150/+400°C |
| Kel-F® | Type 1,2,3 – G | -240/+204°C |
| Back Up and Retainer Materials | Chemical compatibility ** | Max. Temp. °C |
| Nylon | Type 1 – G, Type 2 – S, Type 3 – B | -200/+150°C |
| Nylon 6XAU | Type 1 – G, Type 2 – S, Type 3 – B | -200/+180°C |
| Nylon+Glass | Type 1 – G, Type 2 – S, Type 3 – B | -200/+240°C |
| Peek® | Type 1,2,3 – G | -200/+315°C |
| Peek+Graphite | Type 1,2,3 – G | -200/+315°C |
| PTFE+Carbon-graphite | Type 1,2,3 – G | -200/+300°C |
| AISI 316 | Type 1 e 2 – G, Type 3 – S | -250/+350°C |
| Duplex (F51) | Type 1 e 2 – G, Type 3 – S | -250/+350°C |
| Inconel®625 | Type 1,2,3 – G | -250/+400°C |
| Inconel®718 | Type 1,2,3 – G | -250/+400°C |
| Spring Materials | Chemical compatibility ** | Max. Temp. °C |
| AISI 301 | Utilisation 1-G, Utilisation 2 e 3 – B | -50/+150°C |
| AISI 304 | Utilisation 1-G, Utilisation 2 e 3 – B | -50/+150°C |
| AISI 316 | Utilisation 1 e 2 – G, Utilisation 3 – S | -50/+200°C |
| 17-7PH | Utilisation 1 e 2 – G, Utilisation 3 – S | -50/+200°C |
| Hastelloy® C276 | Utilisation 1,2,3 G | -200/+400°C |
| Inconel® 718 | Utilisation 1,2,3 G | -250/+400°C |
| Elgiloy® | Utilisation 1,2,3 G | -250/+400°C |