Frequently asked questions
The most common questions on hydraulic cylinder selection, manufacturing ranges, standards, testing and export. If your question is not covered, write to our engineering team.
How do you calculate the push force of a hydraulic cylinder?
Push force is F = P × A: system pressure times piston area. Example: a Ø100 mm bore at 200 bar produces about 157 kN (16 tonnes) of push force. For pull force the rod cross-section is subtracted. Our online configurator calculates this live, together with buckling check and seal recommendation.
What is the difference between single-acting and double-acting hydraulic cylinders?
A single-acting cylinder applies hydraulic pressure in one direction only; the return stroke comes from the load or a spring (typical: dampers/tippers, lifting platforms). A double-acting cylinder is pressurised in both directions and is used where controlled force is needed in push and pull (construction machinery, presses, industrial machines). HPS manufactures both types in the Ø25–320 mm bore range.
What is a telescopic hydraulic cylinder and when should it be used?
A telescopic cylinder consists of multiple nested stages and delivers a stroke several times its closed length. It is the right choice when installation space is limited but a long stroke is required: tipper trucks, refuse vehicles, mobile elevating platforms. HPS manufactures multi-stage telescopic cylinders with strokes up to 12,600 mm.
What bore, rod and stroke ranges can HPS manufacture?
Bore Ø25–320 mm, rod Ø15–250 mm. Stroke up to 7,000 mm for industrial cylinders (subject to buckling analysis) and up to 12,600 mm for telescopic cylinders. Rated working pressure 200–250 bar; every cylinder is pressure-tested at 1.5× rated pressure per ISO 10100.
Which seal material should be selected for which operating conditions?
Rule of thumb: NBR for standard applications (≤90°C), HNBR where higher temperature resistance is needed (~120°C), polyurethane (PU) for heavy-duty wear resistance at high pressure, FKM (Viton) for high temperatures and aggressive fluids, PTFE for low friction and high speeds. Final selection is verified by engineering against pressure, temperature and fluid profile; the seal finder on our site does the first screening automatically.
Which standards do HPS hydraulic cylinders comply with?
Design and dimensioning follow ISO 6020-2 and ISO 6022 (high-pressure series), testing follows ISO 10100, system safety ISO 4413, fatigue verification ISO 10771-1. Tube material is DIN 2391 ST52 / EN 10305-1 E355 with EN 10204 3.1 material certification. Mounting types use ISO and NFPA T3.6.7R coding. The company is ISO 9001:2015 certified and products are CE-marked under Machinery Directive 2006/42/EC.
How are cylinders tested before shipment?
Every cylinder passes a test-bench pressure test at 1.5× rated working pressure per ISO 10100 before shipment: internal/external leak check, full-stroke function and drift (holding) verification. On request, a pressure-test certificate and EN 10204 3.1 material certificates are supplied with the product.
What materials are used for the tube and the piston rod?
Tube: DIN 2391 ST52 / EN 10305-1 E355 steel, honed bore to H8–H9 tolerance. Rod: CK45, or 42CrMo4 where higher strength is required, hard-chrome plated at approximately 30 µm and salt-spray (NSS) tested. Material certificates are documented per EN 10204 3.1.
How is rod buckling prevented on long-stroke cylinders?
Design includes an Euler buckling analysis: the minimum safe rod diameter is calculated from stroke, pressure and mounting configuration. If inadequate, the solutions are a thicker rod, a larger bore, a stop tube, or a different mounting geometry. The HPS configurator runs this check automatically and suggests alternatives when needed; industrial strokes up to 7,000 mm are validated with this analysis.
Can HPS manufacture from a sample or a technical drawing?
Yes — custom design is one of our core product families. Customer drawings (PDF/DWG/DXF/STEP) go directly into production engineering; without a drawing, we dimension an existing sample cylinder and produce manufacturing drawings by reverse engineering. Process: request → engineering review → approval drawing → prototype → series production. We work from a single prototype up to series quantities.
Which countries does HPS export to, and under which delivery terms?
We export directly to more than 35 countries, mainly across Europe, the CIS, the Gulf and North Africa. The customs tariff (HS) code is 8412.21. Delivery terms are agreed per project as EXW, FCA, CIP, CIF or DAP; shipments go by road, sea and air freight.
How does HPS supply OEMs (vehicle and machine manufacturers)?
Our core model is direct OEM supply: we produce series cylinders to customer drawings for manufacturers of tippers, refuse vehicles, mobile platforms, forklift attachments, agricultural and construction machinery. Sector-specific cylinder types and spec tables for 11 industries are published on this site; approval drawing + prototype + series delivery schedule are planned per project. All processes (machining, welding, honing, plating, assembly, testing) are in-house in a 20,000 m² plant.
How do I request a quote (RFQ), and what information is needed?
Use the form on the contact page: cylinder type, bore-rod-stroke, working pressure, mounting style and quantity are enough; a technical drawing (PDF/DWG/DXF/STEP, up to 15 MB) can be attached. A configuration made in the online configurator transfers to the form in one click. Your request is reviewed by the engineering team and answered in writing within 1 business day. Phone/WhatsApp is available for urgent cases.