When a hydraulic cylinder has to operate in an environment where magnetic materials may interfere with the application, a standard catalogue configuration may not be sufficient.
In these situations, the cylinder must be designed by considering the complete assembly: body, cartridge, rod and piston, caps, seals, oil ports and hydraulic accessories.
A Vega project provides a good example of this type of customization. The Customer required a special version of a compact V250CE hydraulic cylinder, with carefully selected materials and customized hydraulic connections.
Starting from a Standard Hydraulic Cylinder
The project started from the V250CE family, a compact short-stroke hydraulic cylinder designed for linear movement.
According to Vega’s current product documentation, the standard V250CE is an aluminum-body, double-acting cylinder designed particularly for moving carts, pins and plugs in plastic injection molds. Standard versions are available with bore diameters from 25 to 100 mm and strokes from 20 to 80 mm.
V250CE Short-Stroke Hydraulic Cylinders – Vega Cylinders
However, the application documented in this case had an additional requirement: the Customer wanted to avoid magnetic materials.
Why Material Selection Was Critical
The Customer initially considered a CE025EGDGN020 cylinder but specifically excluded AISI 303 stainless steel because of concerns about its magnetic properties under high magnetic fields.
AISI 316 was therefore requested for the stainless-steel components.
This requirement affected more than one component.
The project documentation specified:
- ERGAL body
- AISI 316 cartridge
- AISI 316 rod and piston
- AISI 316 caps
- special polyurethane seals
- customized 1/4″ BSPT oil ports
The final quotation was for 10 special CE025ESDGN020S cylinders.
This is an important point when designing hydraulic equipment for special environments: material compatibility has to be considered for the complete cylinder rather than only for its main body.
From Standard Product to Special Configuration
Vega normally prefers to supply cylinders and accessories according to standard catalogue configurations.
In this case, however, an exception was made because of the specific requirements of the application and the number of technical details that needed to be defined.
The result was not simply a standard cylinder with a different body material.
The final configuration involved several customized elements.
The special CE025ESDGN020S was specified with:
- ERGAL body;
- AISI 316 cartridge;
- AISI 316 rod and piston;
- AISI 316 caps;
- special polyurethane seals;
- 1/4″ BSPT oil ports;
- maximum working pressure of 150 bar;
- maximum thrust force of approximately 736 kgf;
- maximum traction force of approximately 354 kgf.
Material Certificates Were Part of the Requirement
The Customer also requested certification for the materials used in the cylinder.
The requested materials included ERGAL, AISI 316 and polyurethane.
The final quotation included EN 10204 3.1 certificates for:
- ERGAL used for the body;
- AISI 316 used for the cartridge and rod;
- AISI 316 used for the caps;
- polyurethane used for the seals.
For applications with strict material requirements, this type of documentation can be just as important as the mechanical characteristics of the cylinder.
It provides traceability and allows the Customer to verify that the agreed materials have been specified for the different components.
The Importance of the Sealing System
The special configuration also required polyurethane seals, with a maximum working temperature specified in the quotation at approximately 90–100°C.
The choice of seals cannot be separated from the operating conditions of a hydraulic cylinder.
Temperature, hydraulic fluid, pressure and the materials of the moving components all have to be considered together.
Vega’s product documentation also highlights the importance of selecting the sealing system according to the application and provides special sealing options for particular operating conditions.
Materials and Components of Hydraulic Cylinders – Vega Cylinders
Hydraulic Connections Had to Be Defined Precisely
Another significant part of the project concerned the hydraulic connections.
The Customer was working with hoses featuring fittings with a 60° cone and union nut and needed to understand how these connections could be connected to the cylinder, check valves and flow regulators.
During the discussions, Vega clarified the distinction between cylindrical and tapered BSP connections.
At one stage, the standard oil ports, hoses, check valves and flow regulators were being considered with 1/4″ BSP cylindrical threads.
The final special configuration, however, specified 1/4″ BSPT tapered oil ports on both sides of the cylinder.
This illustrates an important engineering principle:
A thread specification must be precise enough to guarantee compatibility between all components of the hydraulic circuit.
Simply specifying “1/4 BSP” can be insufficient when several different fitting configurations are involved.
The Check Valve Must Be Considered as Part of the System
The hydraulic circuit also included flow regulators and check valves.
Vega specified that the check valve should be installed directly on the cylinder using a rigid connection, rather than at the end of the flexible hose.
This was particularly important because the Customer’s application required the cylinder, check valve, flow regulator and hose to operate as a coordinated hydraulic system.
The project therefore involved more than selecting the cylinder itself.
The complete hydraulic connection had to be considered:
cylinder → fitting → check valve → flow regulator → hose
with the correct thread and connection type at every interface.
Pilot Connections Also Had to Be Checked
During the review of the hydraulic circuit, Vega noticed that the drawing did not clearly show the pilot connections required to unlock the check valves.
The Customer was therefore asked to verify whether a different type of valve was being used or whether the pilot connections were simply missing from the drawing.
This is a good example of why a hydraulic cylinder cannot be engineered independently from its circuit.
A technically correct cylinder can still be installed in an unsuitable hydraulic configuration if the surrounding components and their functions are not properly defined.
Hoses and Fittings Were Also Part of the Design
The project included a substantial quantity of hydraulic accessories.
At one stage, the requested configuration included:
- 10 hydraulic cylinders;
- 18 hoses, each 15 metres long;
- 18 flow regulators;
- 18 check valves;
- 48 connectors.
The hose configuration was also discussed in relation to SAE 100 R1AT tubing, while the exact fitting configuration—straight or 90°—still had to be defined.
This demonstrates another important aspect of customized hydraulic projects:
the accessories must be designed around the cylinder, and the cylinder must be designed around the complete hydraulic installation.
A Customized Cylinder Does Not Always Mean a Completely New Design
One of the most interesting aspects of this case is that the solution was developed around an existing Vega cylinder platform.
The V250CE is already a standard product for compact, short-stroke applications in injection molds. Vega’s current catalogue confirms that the V250CE belongs to its range of cylinders for cart and plug movement in injection molds.
Hydraulic Cylinders for Injection Molds – Vega Cylinders
Instead of developing an entirely new cylinder architecture, the project adapted the platform to the application’s specific requirements.
The customization affected the materials, sealing system and hydraulic connections while maintaining the basic compact-cylinder concept.
This can be an effective engineering approach when a standard platform already provides the required mechanical characteristics but specific application constraints require additional modifications.
Designing Around the Application
The case demonstrates that a successful special-cylinder project begins by defining the application requirements in detail.
For this project, the important questions included:
- Which materials can be used?
- Which materials must be excluded?
- What pressure and forces are required?
- Which sealing materials are appropriate?
- Which thread standard is required?
- Are the connections cylindrical or tapered?
- How will the check valves be installed?
- How will the flow regulators be connected?
- What hose length and fitting configuration are required?
- Which material certificates must be supplied?
Only after these points were progressively clarified could the final cylinder configuration be defined.
The Final Special Cylinder
The final quotation described 10 CE025ESDGN020S special cylinders with an ERGAL body, AISI 316 cartridge and rod-piston assembly, AISI 316 caps, special polyurethane seals and 1/4″ BSPT oil ports.
The specified maximum working pressure was 150 bar, with approximately 736 kgf maximum thrust and 354 kgf maximum traction.
The project also included material certification and a customized hydraulic connection configuration.
The case therefore illustrates an important principle in hydraulic engineering:
a standard cylinder can provide the foundation, but the final solution must be designed around the real requirements of the application.
When material compatibility, magnetic-field exposure, temperature, pressure and hydraulic connections are all critical, customization is not simply an optional feature—it can become an essential part of the engineering process.
