Hydraulic Press Retrofit – Müller Weingarten 250 t (built 1994)

15-inch SIMATIC HMI panel on a retrofitted 250 t Müller Weingarten press with a clear and easy-to-use operator interface — The new SIMATIC TP1500 *touch panel brings operation and messages together in a clear layout. The press can be operated in a transparent, straightforward way – a key factor for acceptance by operators and maintenance.*

This project is one of my most extensive retrofits so far:
The hydraulic Müller Weingarten press (250 t, built in 1994) had been out of operation for at least three years before the retrofit. The control cards for the proportional valves were defective and no longer available.

Why a retrofit instead of a new press?

Purchasing a comparable new machine would have been significantly more expensive.
For the operator, several points clearly spoke in favour of a retrofit:

The press frame and mechanical components are in good condition.
The machine does not need to be transported; the foundation can remain in place.
Existing tools can continue to be used without modification.

Conclusion: The overall cost and effort of a retrofit are significantly lower for the operator than buying a new press.

Complete hydraulic 250 t Müller Weingarten press in original condition before retrofit, technically outdated and out of service for several years — The 250 t Müller Weingarten press in its initial state: technically outdated and out of operation for several years – yet with a solid mechanical base that makes a cost-effective retrofit worthwhile.

Operator side after retrofit, 250-ton Müller Weingarten hydraulic press—new safety control and clear operating concept — The 250 t Müller Weingarten press in its initial state: technically outdated and out of operation for several years – yet with a solid mechanical base that makes a cost-effective retrofit worthwhile.

Electrical system & control

Control cabinet: Cabinet and internal layout were completely rebuilt.
Safety control system:
- Siemens SIMATIC S7-1500F CPU as safety controller
- combined with SIMATIC ET 200SP modules
Visualisation & operation:
- SIMATIC HMI TP1500 Comfort, 15″ touch panel
Command devices:
- New foot switch
- New two-hand control
Measuring systems: renewed.
Cabling: all relevant cables were completely replaced.

Old control cabinet of a 250 t hydraulic Müller Weingarten press with outdated contactor-based control and difficult fault-finding before retrofit — The original cabinet with classic contactor logic: technically outdated, limited diagnostics and time-consuming fault-finding – one of the main reasons for the extended downtime of the press.

Tidy power section of a retrofitted 250 t Müller Weingarten press with clearly arranged star–delta starter and neatly routed cables — The original cabinet with classic contactor logic: technically outdated, limited diagnostics and time-consuming fault-finding – one of the main reasons for the extended downtime of the press.

Safety & finger protection

Finger protection measure:
- BWS 14 mm (Keyence) as a contactless protective device.

Hydraulics

The hydraulic system was also completely replaced and now consists of Rexroth components.

Cylinder control is implemented via a tandem radial piston pump with digital controller:

separately controllable: 250 l/min + 140 l/min
Pmax: 280 bar
in combination with a press safety block

The result is a modern, clearly laid out and precise hydraulic solution that is easy to control.

Old press safety block and hydraulic system of a 250 t Müller Weingarten press with ageing components and partly unavailable valves before retrofit — The old press safety block and hydraulic system had clearly aged; some valves were no longer available. This is exactly the point where many operators face the decision between an expensive new press and a targeted retrofit.

Completely renewed hydraulic system of a 250 t Müller Weingarten press with Rexroth components and tandem radial piston pump after retrofit — The old press safety block and hydraulic system had clearly aged; some valves were no longer available. This is exactly the point where many operators face the decision between an expensive new press and a targeted retrofit.

Project partners & process

The hydraulic system was designed, quoted and installed by Viereck Hydraulik.
The control system and electrical components, including installation, were supplied by me.
The software was developed in cooperation with Wiechern Engineering.
Commissioning on site was then completed jointly within 4 days.
The total retrofit duration at the operator’s site was around 6 weeks.

Standards compliance

In its retrofitted state, the machine fully complies with the requirements of EN ISO 16092-1 and EN ISO 16092-3.