Fluid
Suggestion for the equipment of hydraulic cylinders
The suggestion for the selection of equipment features depends on many operating conditions.
The right equipment is decisive for the quality and reliability of the hydraulic cylinder, for its friction force, as well as the wear behavior of the hydraulic cylinder.
In particular, in addition to the working temperatures and the travel distances and speeds determined in the hydraulic design, the fluid used should be taken into account when determining the equipment:
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Hydraulic oils HLP or HLPD according to DIN 51502 and DIN 51524. HLP is a mineral oil with additives for aging protection and corrosion protection, as well as wear protection. These are most common in hydraulic applications today. HLPD also has detergents and dispersants. Due to demulsifiers, an HLPD oil has better corrosion protection than an HLP oil. It is used in humid environments or in intermittent operation. |
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Fire-resistant hydraulic fluid HFA HFA fluids are oil-in-water emulsions with a water content of over 80%. |
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Fire-resistant hydraulic fluid HFC HFC fluids are aqueous polymer solutions with a water content of over 35%, usually water-glycol mixtures. Their viscosity is similar to mineral oil. |
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Fire-resistant hydraulic fluid HFD HFD fluids are anhydrous, synthetic ester fluids. A distinction is made between HFDR, phosphoric acid esters, and HFDU, which are all other synthetic fluids, such as polyester or di-ester. |
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Brake fluid DOT 4 Brake fluids are hydraulic fluids based on polyglycol. According to standard number 116 of the DOT, United States Department of Transportation, they are divided into three classes - DOT 3, DOT 4, DOT 5. DOT 5 is further subdivided into DOT 5 silicone-based and DOT 5.1 glycol-based. |
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Hydraulic fluids for seals based on PU/ NBR If the fluid used is safely compatible with the sealing materials PU, NBR and PTFE commonly used in hydraulics. This includes, for example, most hydraulic oils HLP and HLPD. |
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Hydraulic fluids for seals based on NBR If the fluid used is safely compatible with the sealing materials NBR and PTFE. This includes, for example, water-containing fluids. |
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Hydraulic fluids for seals based on FKM If the fluid used is safely compatible with the sealing materials FKM and PTFE. This includes, for example, some HFD fluids. |
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Hydraulic fluids for seals based on EPDM If the fluid used is safely compatible with the sealing materials EPDM and PTFE. This includes, for example, brake fluids and some HFD fluids. |
The suggestion given is based exclusively on the operating conditions requested here. No guarantee can be given for their correctness due to any unknown influences that may occur.
If there are further influencing factors, please contact our application consultants.
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