[EN] Bosch Rexroth Web Seminar: Increased system safety with standardized STO Manifolds (STOM)

Connected Hydraulics Web Seminar: System Safety in Manifolds

Introduction to the Seminar

• The seminar marks the last edition of the Connected Hydraulics Web Seminars for the year, hosted by Stefan Lehnert.

• Stefan introduces Marvin Meiling, an expert on system safety in manifolds, who will co-present during the session.

Overview of Functional Safety in Hydraulics

• Marvin emphasizes the importance of understanding functional safety in hydraulics, especially for OEMs and end users involved in machine building or retrofitting.

• He introduces the concept of "STO manifold" (Safe Talk Off), which is a new product aimed at enhancing system safety.

Risk Analysis and Assessment

• Discussion on risk analysis highlights that every machine requires a thorough assessment to identify potential hazards affecting personal safety.

• Marvin outlines three levels of risk reduction:

• Designing machines to prevent risks (e.g., physical barriers).

• Implementing technical protective measures like light curtains that control machine operations based on detected hazards.

• Providing user information as a final measure to enhance operator awareness.

Performance Levels and Risk Graph

• The performance level quantifies how often dangerous failures may occur within a specific timeframe, guiding necessary safety measures.

• A risk graph is introduced as a tool for determining required performance levels based on injury severity and frequency of exposure to hazards.

Audience Engagement and Challenges in Machine Safety

• An interactive poll gauges how frequently participants encounter issues related to machine safety; results show varied experiences among attendees.

• Participants are prompted to share challenges they face regarding machine safety, including hazard identification and determining appropriate performance levels.

Transitioning to Product Focus: STO Manifold

• The discussion shifts towards specific products, particularly focusing on the newly developed Safe Talk Off Manifold as part of their product family.

Understanding the STO Manifold and Its Safety Functions

Overview of Hydraulic Control Systems

• The discussion begins with the importance of hydraulic control in systems with larger or central oil supplies, emphasizing the need for individual control of different machine sections.

Safety Features and Standards

• The STO manifold serves as an area shutdown mechanism to interrupt hydraulic pressure supply, aligning with safety norms such as ISO 13849, specifically achieving category 4 and performance level E.

Performance Levels Explained

• Achieving higher performance levels requires specific system architecture; for instance, two monitored valves are necessary to meet performance level E in functional hydraulics.

Safe Torque Off (STO) Functionality

• The term "safe torque off" translates to "safe energy separation" in hydraulics, which involves cutting off fluid flow and pressure from P1 to P2. This includes a sub-function called safe decompression (SDE).

Additional Functions of the STO Manifold

• The manifold can also facilitate safe limited speed or volume flow functions, contributing to personal and machine safety requirements according to current standards.

Applications and Benefits of the STO Manifold

Key Applications Identified

• Main applications include central oil supplies, testing areas, and metallurgy plants where high volume flows (200 - 1000 liters per minute) are common.

Individual Machine Control Capabilities

• The STO manifold allows for individual blocking of machine parts; this enables safe loading/unloading or maintenance on one part while others continue operating.

Enhancing System Availability

• By allowing simultaneous operation of different machine parts, the system not only ensures safety but also increases overall availability.

Safety Functions in Hydraulic Systems

Commonly Used Safety Functions

• Typical safety functions discussed include safe stop, safe torque off, safe de-energizing/decompression, and limited speed/volume flow options.

Focus on Performance Levels

• Feedback indicates that most participants require performance level D for their work; however, there is a mix between levels C and E among responses.

System Setup Phases for STO Manifolds

Schematic Overview

• A schematic representation shows an STO manifold capable up to category 4 PLE with active logics represented by main valves.

Default State Operations

• In its default state, all valves are de-energized while spool monitoring is active. Pressure from P1 safely closes valves while P2 is decompressed to a leakage port.

Pre-compression Process Explained

• To manage large dead volumes in central oil supplies effectively, bypass functions allow pre-compression of the P2 line before activating main valves.

Demonstrating Manifold Technology and Safety Features

Overview of Manifold Testing

• The testing of manifolds aims to dampen switching strokes, enhancing component lifespan and reducing noise levels. This is demonstrated through a video showcasing the test bench results.

Video Demonstration Insights

• In the initial part of the video, a hard open of the STL manifold produces significant sound and movement in the hose, indicating high switching strokes. Following this, a decompression mode is shown which reduces these effects significantly.

• The importance of pre-compression functions is highlighted as they are crucial for managing larger volumes (300 liters/minute) in customer systems, particularly in metallurgy applications where volumes can reach hundreds of liters.

Flow Characteristics and Energy Efficiency

• The manifold operates efficiently across various flow rates (300 to 1000 liters/minute), with energy efficiency being a key focus due to advanced valve technology used in STO manifolds. Different sizes are available to meet specific volume flow requirements.

• Active logic valves feature elongated holes that enhance energy efficiency by approximately 30%, which is significant given the high volume flows involved. This design also contributes to reduced noise levels during operation.

Safety Mechanisms in Manifold Operation

• A fail-safe mode activates when an obstruction (like a hand) enters the light curtain; all valves de-energize immediately, ensuring rapid decompression and shutdown for safety purposes. This mechanism emphasizes quick response times under pressure conditions, achieving closing times below 300 milliseconds during development phases.

• The system's design allows for easy integration into existing setups with consistent hardware and electrical control across different manifold sizes, simplifying installation processes for users.

Performance Levels and Options

• While performance level E (category four) offers high safety standards, options exist for lower performance needs (level D or category three). By utilizing pressure sensors instead of direct monitoring on bypass valves, cost-effective solutions can still maintain adequate safety measures within systems requiring less stringent performance levels.

New Product Family Overview

Introduction to the Product Group

• The discussion begins with an overview of a new product family, emphasizing the option to use either a bypass function or a base function with cover plates on Psi6 valves.

• The speaker notes that while these products are standardized and available for order post-launch, the range of the portfolio is limited.

Selection Process for Products

• An example is provided where NBR material and size 32 are chosen for a flow rate of 1000 liters per minute, leading to only three remaining options based on decompression and compression functions.

• The datasheet for these products is currently in translation, expected to be available by mid-December or early January.

Advantages of Standardization

• Highlighting benefits, it’s noted that existing knowledge from development aids in risk assessment and compliance with safety regulations.

• The efficiency gained through standardization allows customers to quickly select appropriate manifolds without extensive setup time.

Efficiency and Availability

Speed of Acquisition

• The process of selecting a manifold is significantly faster compared to traditional methods involving bill of materials and schematics, enhancing both sales efficiency and customer experience.

Documentation and Support

• A separate manual will be created specifically for these manifolds detailing electrical control operations, signal monitoring, and safe operation guidelines.

• CAD models will also be made available to support engineers' needs during design phases.

Technical Questions Addressed

Logic Graph Connections

• A question regarding different connections (A to B vs. B to A) reveals that simulations showed equal energy efficiency but improved flow differentiation with ABBA configurations.

Size Variability

• In response to inquiries about larger sizes than NG40, it was confirmed that scaling up manifolds for higher volume flows (LC50 or LC60 versions) is feasible upon customer request.

Safety Regulations and Energy Efficiency

Compliance Necessity

• Emphasizing safety regulations as paramount, it's stated that fulfilling these requirements may introduce additional pressure loss but remains essential for operational legality.

Energy Efficiency Ratings

• High energy efficiency ratings are highlighted alongside ongoing efforts to assist customers in calculating total cost of ownership (TCO), ensuring optimal performance within specified volume flows ranging from 200 to 2,000 liters per minute.

Manifold Certification and Advantages

Overview of Manifold Sizing and Pressure Loss

• If 10 bars is excessive for a customer, selecting a larger size is recommended. This may result in three to five bars of pressure loss, which can be acceptable if energy efficiency requirements are met.

Certification Process

• The speaker mentions ongoing discussions with the TIF association regarding certification for the manifolds, with an expected official certification by the end of February. This indicates proactive steps towards compliance and quality assurance.

Advantages of Manifolds

• Key advantages include personal safety and energy efficiency. The manifolds can accommodate special fluids like HFC or HFDU, ensuring compatibility in metallurgy applications while providing leakage-free shutoff from P1 to P2.

Design Benefits

• The compact design of the manifold leads to reduced project planning time and faster development cycles for customers, optimizing supply chains through fully assembled and tested control blocks. This highlights efficiency in both production and application phases.

Summary Insights

• A comprehensive overview was provided on STO manifolds, including practical application examples that illustrate their benefits across various phases of use. The session concluded with gratitude expressed towards participants for their engagement and interest in the topic.

Further Information and Contact Details

Accessing Additional Resources

• Participants will receive written information about the web seminar upon registration, along with access to extensive online resources related to manifold technology available on their landing page. This ensures continued learning beyond the seminar itself.

Upcoming Publications

• An article from Euroblech is anticipated that will include data sheets and manuals relevant to manifold technology, expected before Christmas this year, indicating ongoing efforts to provide updated resources for users.

Specialist Support Availability

• For specialized inquiries or projects, Marvin is available as a contact point alongside local sales representatives who can assist with general questions about products or services offered by the company. This emphasizes support accessibility for customers needing tailored assistance.

Production Start Dates and Safety Calculations

Production Timeline

• Official start of production (SOP) coincides with uploading necessary documentation such as data sheets and manuals; thus ensuring readiness when launching new products into the market while supporting customer needs effectively during this transition phase.

Safety Calculations Offered

• Customers interested in STO manifolds can request performance level calculations that validate safety levels; these calculations were completed during product development stages ensuring reliability when presented to clients seeking assurance on safety standards adhered to by products offered.

Feedback Request & Future Seminars

Gathering Participant Feedback

• Attendees are encouraged to provide feedback regarding their experience at this web seminar; insights gathered will help improve future sessions reflecting participant satisfaction levels concerning content delivery effectiveness.

Next Seminar Announcement

• The next web seminar scheduled for February will focus on high-performance pumps featuring colleagues from the pump department located in Southern Germany; participants are invited back for further exploration into related topics within fluid dynamics technologies.