Pneumatic Safety Certifications updated with Ross Controls

TROY, MI – ROSS CONTROLS is pleased to announce that its DM2® Series C safety valves have received third-party certification from the BG (Berufsgenossenschaften- German Institute for Occupational Safety and Health). On July 8, 2009, the BG deemed the DM2® Series C products suitable for ISO 13849-1:2006 Category 4 PL e applications. The ISO 13849-1:2006 standard (Safety of Machinery, Safety-related Parts of Control Systems) will replace the EN 954-1 standard as of November 30, 2009. This certificate is available on the ROSS Web site at www.rosscontrols.com or upon request from ROSS Customer Services.

All valves in the ROSS DM2® product line meet global requirements for machine safety and are commonly used for exhausting the downstream air to help meet stop-time requirements in machine guarding applications. Because many safety systems incorrectly focus solely on the electrical design and overlook mechanical elements, ROSS created the DM2® pneumatic double valve family to address this issue knowing that effective safety systems do not end at the electrical wire.

For enhanced performance and value, memory, monitoring, and airflow control functions are simply integrated into two identical valve elements. DM2® pneumatic safety valves lock out due to asynchronous movement of valve elements during actuation or de-actuation, resulting in a residual outlet pressure of less than one percent of supply. Overt action is required for reset, and reset can only be accomplished by applying a remote air signal or by energizing the integrated electrical (solenoid) reset. These ROSS safety valves are base-mounted and are available in 1/2” to 1-1/2” ports sizes with NPT or BSPP threads.

Additionally, all DM2® valves will be labeled with the CE (Conformite Europeenne) mark to comply with the New Machinery Directive (2006/42/EC) that takes effect in the European Union as of December 29, 2009. This directive defines the requirements for the CE marking of products, requires the CE mark on safety components, and specifically includes “…valves with additional means for failure detection intended for the control of dangerous movements on machinery.” The “Declaration of Conformity” document is available on the ROSS Web site at www.rosscontrols.com or upon request from ROSS Customer Services.

Safety Locks Lift Italian Opera House Stage

With theater performances, the illusion of a reality on a stage must be preserved seamlessly and without visual distraction. Safety of the performers, however, must never be an illusion. 

The stage lifts at the opera house in Genoa, Italy are equipped with safety locks to prevent movement in the event of power loss. The motion of these lifts, each capable of bearing loads to 100,000 lb, is maintained by hydraulic cylinders equipped with SITEMA safety locks Type KRG. In normal power-on conditions, pressure on the lock’s annular piston ensures free movement of the cylinder rod by holding the clamping sleeve released against the force of an integral Belleville spring assembly.

Safety locks were installed with these cylinders at a Italian opera house.

In a released position, that is, upon loss of power to the cylinder, the annular piston keeps the clamping sleeve pushed against the Belleville springs.  The spring washers press the clamping sleeve into the taper of the housing, whereby an initial frictional force develops between the rod and the clamping sleeve.  When load is applied, the force increases, so the higher the load, the stronger the clamping.  In normal applications, the safety locks function best for loads from 2 kN to 500 kN (220 to 110,000 lb).   

When the load acts on the rod, the rod movement is very slight.  Even in the largest sizes, the movement does not exceed 2 mm (0.079 in.) for the permissible load.  Against forces in the load direction, the higher the force the stronger the grip.  When power is restored, the upward movement of the rod releases the clamping and a proximity sensor/switch detects the change and permits unimpeded downward motion.  

Safety locks ensure that stages stay in place, even through a power loss.

The rod end used for these safety locks must be fitted with a lead-in chamfer and the rod surface should be hardened to at least HRC 52, burnished and within ISO tolerances f7 or h6, with a surface finish Rz=1 to 4mm or Ra 0.15-0.25mm.  Hard chrome plating is recommended.  

SITEMA 
www.sitema.com