Install­a­tion informations

Design require­ments

The lead-in cham­fers on rods, shafts and bores must be provided for the dif­fer­ent seals as shown in the illus­tra­tion for each install­a­tion situation.

Plastic and elast­omer seal­ing and wiper/scraper ele­ments must not be pushed over sharp edges, thread crests, cross holes, grooves or rough sur­faces. This aspect must be con­sidered in the design phase or dur­ing construction.

If this is not the case, these points must be covered before installation.

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Gen­er­al install­a­tion information

Com­pon­ents and tools must be cleaned before install­a­tion.

Sharp-edged tools must nev­er be used dur­ing install­a­tion. Con­sider the effect­ive dir­ec­tion when installing uni­direc­tion­al elements.

On slid­ing rings and wipers/scrapers the parts may be greased or oiled.

On elast­o­mer­ic parts and O-rings made from EPDM, SBR, IIR or CR, do not use min­er­al oil or grease, only sil­ic­one oil.

For shaft seals (par­tic­u­larly types 231; 233; 234 and 238), the groove (hous­ing) must be degreased before install­a­tion. Grease or oil must not pen­et­rate into the groove and between the O-ring and the pro­file ring dur­ing installation.

Dur­ing final install­a­tion and when care­fully join­ing the com­pon­ents, the con­tact sur­faces between the seal and the mat­ing sur­face may be greased or oiled to reduce the mount­ing forces.

Res­iz­ing can also be car­ried out through the mat­ing sur­face (cyl­in­der bore or rods). They must have a lead-in cham­fer of suf­fi­cient size for this purpose.

When using oil or grease, make sure that the mater­i­als are compatible!

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Install­a­tion of out­er seal­ing ele­ments in recessed grooves

When installing seals with an O-ring ener­gizer in a recessed groove, first place the O-ring in the seal groove, then fit the seal­ing ring. With type 314 and 354 seals it may be con­veni­ent to install the seal­ing ring and O-ring togeth­er in one operation.

The use of assembly aids or tools is recom­men­ded for plastic seals.

… without assembly tool

If the lead-in cham­fer on the pis­ton is of suf­fi­cient size, the seal­ing ring can be installed dir­ectly. Seal­ing rings are easi­er to fit if they are heated to 80 to 100°C in oil, water or the oven. Do not exceed the max­im­um tem­per­at­ures for the mater­i­als used.

The seal is res­ized with a res­iz­ing tool or a cyl­indric­al tube; this requires a lead-in cham­fer of suf­fi­cient size. The cham­fer should be sized as shown in the design dimensions.

… with assembly tool

Spe­cial assembly tools con­sist­ing of install­a­tion cone, expan­sion sleeve and res­iz­ing tool are suit­able for series install­a­tion of ‘out­er act­ing seals’.

To avoid dam­age to the seal and com­pon­ent, the assembly tool should be made from a plastic with good slid­ing prop­er­ties (e.g. poly­am­ide, POM).

The seal­ing ring should be stretched as little as pos­sible dur­ing install­a­tion and then only briefly. There­fore a thin-walled install­a­tion cone should be used.

The more quickly the install­a­tion pro­cess is com­pleted, the bet­ter the seal­ing rings snap back to their ori­gin­al size in the groove. If the expan­sion for install­a­tion is not reversed quickly enough, the ele­ments must be put back into shape with a res­iz­ing tool before final installation.

If the cham­fer­ing on the bore is long enough, install­a­tion is pos­sible without pre-sizing.

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Install­a­tion of inner seal­ing ele­ments in recessed grooves

To install seals with an O-ring ener­gizer in a recessed groove, first place the O-ring and then the seal­ing ring in the hous­ing. With type 316 and 356 seals it may be con­veni­ent to install the seal­ing ring and O-ring togeth­er in one operation.

The use of assembly aids or tools is recom­men­ded for plastic seals.

… without assembly tool (seal folding)

Seal­ing rings with a large inside dia­met­er can be installed without an assembly tool.

Install­a­tion begins with the O-ring. Then the seal­ing ring is fol­ded into a kid­ney shape with no kinks. This shape makes it easy to place it in the groove.

Once in the groove, the ‘kid­ney’ is unfol­ded and reshaped to a circle by hand. Finally the seal must be res­ized, either with a res­iz­ing man­drel or with a res­iz­ing rod if the cham­fer­ing is long enough.

The dis­ad­vant­age is that the loop can­not be fully reshaped and a ‘resid­ual kink’ is left. This causes slight leak­age, par­tic­u­larly with small dia­met­ers and low pres­sures, but this is reduced on run-in.

… with assembly tool

For series install­a­tion of ‘inner act­ing seals’ the use of assembly tools con­sist­ing of install­a­tion sleeve, com­pres­sion man­drel and res­iz­ing man­drel is recommended.

The parts should be made from a plastic with a good fin­ish and good slid­ing prop­er­ties (e.g. Poly­am­ide, POM) to pre­vent dam­age to the seals and components.

The seal­ing rings should be com­pressed as little as pos­sible dur­ing install­a­tion and then only briefly. There­fore a thin-walled install­a­tion sleeve should be used.

The more quickly the install­a­tion pro­cess is com­pleted, the bet­ter the seal­ing rings snap back to their ori­gin­al size in the groove. If the seal­ing ring pro­jects too far inside due to the assembly deform­a­tion, the seal must be put back into shape with a res­iz­ing man­drel before final install­a­tion. If the cham­fer­ing on the rods is long enough, install­a­tion is pos­sible without pre-sizing.

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Assembly tools

Due to the dif­fer­ent dimen­sions and spe­cif­ic applic­a­tion con­di­tions, these assembly tools can­not be sup­plied as stand­ard. They are avail­able on request but a draw­ing of the rel­ev­ant com­pon­ent is required.

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Install­a­tion in open grooves

Split hous­ings are install­a­tion-friendly and are gen­er­ally recom­men­ded because the seal is not deformed.

Split hous­ings are a require­ment for flange-clamped and/or spring-loaded seals. The install­a­tion sequence should be suit­able for the seal structure.