What is a hydraulic wiper?

A hydraulic wiper is installed on the outside of the cylinder head around the piston rod. The wiper lip runs along the surface of the rod and removes contaminants as the cylinder retracts.

Without effective wiping, dirt particles can enter the cylinder via the piston rod. These contaminants can pollute the hydraulic oil and subsequently damage seals, guiding elements, pumps and valves.

First line of protection for the hydraulic cylinder

The wiper forms the first barrier between the external environment and the internal sealing system. Proper wiping performance is particularly important for machinery operating outdoors or in contaminated environments.

Hydraulic wipers for open or closed grooves

The design of the mounting groove in the cylinder head determines which type of hydraulic wiper can be used. A design intended for a closed groove is not automatically suitable for an open bore. When selecting a wiper, it is therefore important to consider not only the dimensions and material, but also the groove design.

Closed groove

In a closed groove, the wiper is installed in a housing that is enclosed on both sides. Elastomer or plastic profiles are often used for this type of installation.

Open groove

With an open bore, the wiper is pressed into the cylinder head from the outside. Designs with a metal core or metal casing are often used for this purpose to provide sufficient retention in the bore.

Examples of mounting grooves for hydraulic wipers

The drawings below illustrate the difference between an open groove, a closed groove and a closed groove for a double-acting wiper. The shape of the mounting groove is an important factor when selecting the correct wiper profile.

Open groove

Closed groove

Closed groove – double-acting

Single-acting and double-acting hydraulic wipers

Most hydraulic wipers are designed primarily to remove contaminants and operate in combination with a separate rod seal. Combined designs are also available.

Single-acting wiper

A conventional wiper removes contaminants from the piston rod as it retracts. Hydraulic pressure is sealed by a separate hydraulic rod seal.

Combination wiper

A combination wiper combines wiping and sealing functions in a single profile. This can be particularly useful where installation space is limited. The condition of the piston rod and the operating conditions should be carefully considered when selecting this type of wiper.

Materials for hydraulic wipers

Hydraulic wipers are available in various elastomers, plastics and material combinations. The appropriate material depends on factors such as wear, temperature, operating medium, speed and the level of contamination.

Polyurethane (PU)

PU is widely used for hydraulic wipers because of its high wear resistance and good mechanical properties. It is suitable for many applications involving mineral-based hydraulic oils.

NBR

NBR is a cost-effective choice for general hydraulic applications and provides good resistance to many mineral oils and greases.

FKM / Viton

FKM/FPM, commonly referred to as Viton®, can be used where higher oil temperatures or improved chemical resistance are required.

PTFE

PTFE offers very low friction and broad chemical resistance. Depending on the design, PTFE wipers can be energised by one or more O-rings.

Polyester and metal designs

For more demanding scraping applications, polyester or designs with a metal reinforcement or metal case can be used. Metal-cased designs are particularly suitable for installation in open housings.

Environment and contamination

The environment in which a hydraulic cylinder operates has a major influence on the choice of hydraulic wiper. Not every application requires the same wiping performance.

Construction, earthmoving and agriculture

On excavators, agricultural machinery and cranes, the piston rod may be exposed to sand, mud, grit and moisture. A wear-resistant profile with effective wiping performance is important in these conditions.

Clean industrial environments

In a relatively clean production environment, a highly aggressive wiping lip is not always necessary. A lighter profile can help reduce friction and wear on the piston rod.

Interaction between the wiper and rod seal

A hydraulic wiper works together with the hydraulic rod seal. Both components should therefore be considered as part of a complete sealing system.

During extension, a very thin oil film remains on the piston rod. This lubricating film helps reduce friction and should be able to return towards the cylinder when the rod retracts.

Excessive wiping action

If a wiper prevents the oil film from returning effectively, oil can accumulate between the wiper and the rod seal. This can result in pressure build-up between the two sealing elements and may eventually cause leakage.

Guiding and condition of the piston rod

For consistent operation, the piston rod must be guided correctly. Misalignment or side loads can cause the wiper lip to be subjected to greater loads on one side.

For recurring problems, the hydraulic guide rings and hydraulic guide strips should therefore also be inspected.

Damaged piston rod

Scratches, corrosion, pitting or other damage to the piston rod can accelerate wear of both the wiper and the rod seal behind it.

Determining hydraulic wiper dimensions

Four important dimensions are generally required when selecting a hydraulic wiper.

Inside diameter (d)

The inside diameter (d) corresponds to the diameter of the piston rod along which the wiper lip moves.

Outside diameter (D)

The outside diameter (D) is determined by the groove or housing in which the wiper is installed.

Groove width (L)

The groove width (L) is measured in the longitudinal direction of the cylinder.

Overall height (h)

The overall height (h) represents the complete height of the wiper profile. For certain designs, the installation height may also need to be measured separately.

When measuring a worn or deformed wiper, it is preferable to measure the piston rod and mounting groove directly. Always specify whether the installation uses an open or closed groove.

When should a hydraulic wiper be replaced?

A worn hydraulic wiper may no longer remove contaminants effectively from the piston rod and should therefore always be inspected during cylinder overhaul or maintenance.

Damaged wiper lip

Check for cracks, worn edges, cuts, hardening or deformation. A damaged lip may no longer make proper contact with the piston rod around its entire circumference.

Contamination inside the cylinder

If significant amounts of sand, dirt or other contaminants are found behind the wiper during disassembly, this may indicate that the wiping performance has been insufficient.

Applications of hydraulic wipers

Hydraulic wipers are used in virtually every hydraulic cylinder where a piston rod extends outside the cylinder.

Construction and earthmoving machinery

On excavators, cranes, aerial work platforms and earthmoving equipment, wipers protect hydraulic cylinders against sand, mud and other coarse contaminants.

Agricultural machinery

Hydraulic wipers are also important in tractors, agricultural machinery and telescopic cylinders due to exposure to dust, soil and moisture.

Industrial hydraulics

Other applications include forklift trucks, lifting equipment, industrial presses, marine equipment and material-handling machinery.

Hydraulic wipers in different brands and sizes

Techniparts supplies hydraulic wipers from various manufacturers. Existing wipers can often be identified by their type number, material, profile and dimensions.

This makes it possible to find either an original type or a technically equivalent alternative for many existing machines. Cross-reference information can be used to compare type designations from different manufacturers.

Custom-made hydraulic wipers

For older machinery, inch sizes and non-standard grooves, custom hydraulic wipers can be produced. Where possible, provide the piston rod diameter, groove diameter, groove width, height, material and operating conditions.

Wiper seal brands and equivalents

Techniparts supplies wiper seals from various well-known manufacturers. The overview below shows common types and materials by brand. This can help identify an existing wiper seal or find a suitable alternative.

Logo	Brand	Types	Materials
	Freudenberg Sealing Technologies	PU 5, PU 6, PU 11, P 8, P 9, PT 1, PT 2, AUAS, AUPS, AS, ASOB, AUPS, AUASOB, P6, PU5, PU6, PU11, PT1, PT2, P8, P9, PRW 1	PU, polyurethane, PTFE, NBR, Viton, HNBR, 95 AU V149, 95 AU V925, Disogrin
	Dichtomatik	AD 48 (AD48), AD 51 (AD51), AD 60 (AD60), ADM 55 (ADM55), AE 40 (A40), AE 41 (A41), AE 42 (A42), AE 47 (A47), AM 43 (AM43), AM 44 (AM44), AM 45 (AM45), AM 55 (AM55)	NBR, EPDM, PUR/TPU, polyurethane, PTFE, bronze, graphite
	Angst & Pfister	LWPU5C, LWPU6C, LWPU7C, LWPU8C, LWPT1C	NBR, PUR/AU, PTFE
	Bal Seal	Series 13, 14	UHMW-PE, PTFE, glass/MoS₂, carbon fibre, TA, G, GC, GFP, GFPM, GL, SP, UPC, FDA
—	Claron	PWB, PWO, PWS, PWM, WM, PWE, CSW, CSWM, PMW, PFB, PFP, UPWM, PWD, EW, 931, 941, 951, PWH, PWN, PWC	NBR 70 Shore, NBR 90 Shore, AU, polyurethane
	Dichta	DAS, DP6, DP7, DP8, DRS, DWR	NBR, polyurethane, PUR, polyester, PTFE, FKM/Viton
	DLI Seals	B, MDK, ICL, MWM P, IWM, MWS, IWS, WRM, EWS	NBR, TPU
	ERIKS	RX, EHD, MES, 930, 007F EMF, 008N, 007N EMN, 006P	NBR, FKM/Viton, FPM, EPDM, PU/AU, polyurethane, brass, stainless steel, PTFE
	EVCO	590, EPA, GHK, GHW, GPW, GPY, RCM	PTFE, PU, polyurethane, AU, NBR
	Guarnitec	GHM, GHK, GHY, GHW, GPA, GHP, GPW, GHF, GGW	AU, PU, NBR, rubber-metal
	Hallite	38, 33, 520, 831, 834, 839, 842, 846, 860, 862	NBR, polyurethane, PUR, polyester, PTFE
	Hecker	AB, ABR, ABP, ABR1, ABR2, ABR3, ABF1, ABF2, ABP1, ABP2, ABP3	Rubber, NBR, PTFE, PU, AU, GI
	Hunger	AI, AI-D, AIST, A-EIS, A-EIS-S, A-EIS-SL	NBR, PU, PTFE, POM, PA6, PA-CF, UHMW-PE, PEEK, Hytrel, MVQ, FPM, FMVQ
	James Walker	Wiper L Split, Wyclip Heavy Duty, Scraper W3 Lionsele	NBR, polyurethane, PU
	JM Clipper	SSW, P, H	FPM, NBR
	KACO	QAN (NM), QHW (NGU, VGF, NGF, VGFU), QHLH (VGU), QHLP (RGU), QFN (VG), QFS, QVN PVS (NF)	NBR, ACM, VMQ, FKM, FPM
	Kastas	K05, K06, K07, K09, K10, K11, K12, K27, K703, K30, K52	PU, NBR, steel, polyurethane
	Nordex	ARAN, AWSW, AWBB, AWSN	PU, polyurethane
	Parker	A1, A2, AM, AH, AF, AY, A5, A6, A7, Y3, Y4, AD, AG, AT, W7 Poly-Pak, P5008, P5009, P6000, P5004, P5000, P5001, P5062, P5075, P5007, P5070, P5011, P5080, P5010, P5012, P4300, P5500, N3571, N3570, N3578, N3580, N3584, N3582, E3676, E8536, E8608, V3664, V3656, V3638, V3681	NBR, polyurethane, FKM/Viton, HNBR, PTFE
	Polilas	PT, PT1, PTM, PBT, PBT1, PBS, PTS, PTS1	NBR, AU, PU, polyurethane
	Polypac / Sealtech	WRM, WRMP, WRMC, WTF, DSR, DSR U UP, 10, DK, DSR/P, 10GA, GA P, GA R, NW, PPW, PWB, PW G U, SWP, UWR, UWR/P, UWR/PI, UWR/PN, WRM-H, WRM-P, WRM-PI, WRS, DR	NBR, HNBR, MVQ, FPM, EPDM, Viton, PTFE, polyurethane, PUR, AU, HDPE, PA, PF, PBTP and various PU compounds
	SKF	A01-A, A01-B, A02-A, A02-B, A02-I, A03-A, A04-A, A04-B, A07-A, A08-A, A08-B, A09-A, A10A, A11-A, A11-I, A12-A, A13-A, A25-F, A26-F, A27-F	Ecopur, TPU, CPU, NBR, HNBR and various SKF compounds
	Trelleborg Sealing Solutions	Excluder 2, Excluder 5, Excluder 500, DA22, DA24, ASW, WNE, WNV, WRM/PC, WP, WRM/C-WSA, WRM, DA17, Turcon T01, T05, T10, T12, T16, T19, T24, T25, T29, T40, T42, T46, T47, T51, T52, T59, T78, T99, M12, Q2J, MO2, M83, Zurcon Z201, Z20, Z22, Z24, Z43, Z431, Z48, Z51, Z52, Z80	NBR, FKM, HNBR, EPDM, FFKM, PTFE/Turcon, PUR/Zurcon, UHMW-PE

Wiper seal cross-reference chart

Use the wiper seal cross-reference chart below to compare Techniparts profiles with equivalent or comparable references from Freudenberg, Hallite, Dichtomatik, Trelleborg, Parker, Sealtech, Kimman and FPE Seals.

The references are intended as an identification and cross-reference guide. Before ordering, always check the dimensions, profile, material, groove design and operating conditions. A corresponding reference does not necessarily mean that every version is technically identical.

Profile	Material	Techniparts BV	Freudenberg	Hallite	Dichtomatik	Trelleborg	Parker	Sealtech	Kimman	FPE Seals
	NBR	WS-10	P6	33	AE 40	WRM	A5	WRM	WSM	-
	PU	WS-10	PU6	831	AE 42	WRM	A5	WRM-P	WSM-P	MSWE
	NBR	WS-11	ASOB	-	AE 41	ASW	A1	DSR	DP8-H9	-
	PU	WS-11	AU ASOB	834	AE 47	ASW	A1	DSR/P	DP8-PU1	MSWS
	Polyester	WS-17	-	38	AE 38	-	-	WRM-H	WSM/HP	MW38
	NBR - Metal	WS-20	AS	37	AD 51	WSA	AM	GA	DAS-H9	MCWN
	NBR - Metal	WS-21	P7	32	AD 53	-	-	GA/R	RS-H9	-
	PU - Metal	WS-22	AUAS	860	AM 43	WRM-PC	-	PW	P/DAS	MCWE
	PU - Metal	WS-23	AUPS	862	AM 54	SWP	*AF*	SWP	SWP-PUR	MCWI
	NBR	WS-D14	P8	-	AD 51	DA17	-	DSR/UP	DA17-N90	MSWHN
	PU	WS-D14	PU8	-	-	DA17	-	-	-	-
	NBR	WS-D15	P9	839N	AD 53	DA22	AY	UWR	UWR	-
	PU	WS-D15	PU 11	839	AD 48	DA22	AY	UWR/P	UWR/P	MSWH
	NBR - Metal	WS-D24	-	-	ADM 55	-	-	PW	-	-
	PU - Metal	WS-D24	-	-	-	-	-	PW/U	DAS/SCB/PU	MCKBI
	PTFE / NBR	WS-30	-	-	A 80	Excluder	-	-	-	-
	PTFE / NBR	WS-D31	-	E2W	AD 60	Excluder 2	-	WE 3	TF 157	MWTF
	PTFE / NBR	WS-D32	-	A5W	AD 61	Excluder 5	-	WE 5	TF 159	MWTF

Is your current type not listed? Send us the brand, type number, material and dimensions of the existing wiper seal. If possible, also include a photograph or technical drawing. We can then help identify a suitable Techniparts profile or technical alternative.

Other seals for hydraulic cylinders

When overhauling a hydraulic cylinder, it is advisable to inspect not only the wiper but also the other sealing and guiding elements.

Hydraulic rod seals are used to seal the moving piston rod and help prevent hydraulic fluid from leaking out of the cylinder.

Hydraulic piston seals are used to separate the pressure chambers inside the cylinder.

Hydraulic guide rings and guide strips support and guide the moving components and help prevent unwanted metal-to-metal contact.