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.

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!

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.

Instal­la­ti­on and resi­zing of outer sealing ele­ments with spe­cial assem­bly tools
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.

Sealing ele­ment for inser­ti­on into the bore, fold­ed into a loop

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.

Instal­la­ti­on and resi­zing of inner sealing ele­ments with spe­cial assem­bly tools

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.

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.

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.