MTS Series 311 Load Frame - Manual (Page 25)

Series 311 Load Frame Safety 25
• Ensure that all pressurized air or gas is bled out of a pneumatic or gas-
charged device before you start to disassemble it. A thorough understanding
of the assembly and its pressurized areas is necessary before you undertake
any maintenance. Refer to the appropriate product information for the
correct bleeding procedure.
It might not be obvious or intuitive which bolts or fittings are used to
restrain a pressurized area. On some assemblies, you must remove a cover
plate to gain access to the structural bolts. Sometimes, to protect you from a
rapid release of trapped gases, a small port is exposed when you remove this
cover plate. Exposing this port ensures that the gas precharge is fully bled
before disassembly. However, this is not the recommended procedure for
bleeding a pneumatic or gas-charged device, because it can expose you to
the dangers of escaping compressed gas and particulates that are expelled
from the chamber or around the seals. Do not assume that cover plates and
ports are installed in all the critical locations.
Consult MTS when in doubt about the safety or reliability of any system-related
procedure or modification that involves devices that contain any type of
compressed gas.
Check bolt ratings and
torques
To ensure a reliable product, fasteners (such as bolts and tie rods) used in MTS-
manufactured systems are torqued to specific requirements. If a fastener is
loosened or the configuration of a component within the system is modified, refer
to the system and component assembly drawings (located on the System
Documentation CD) to determine the correct fastener, fastener rating, and torque.
Overtorquing or undertorquing a fastener can create a hazardous situation due to
the high forces and pressures present in MTS test systems.
On rare occasions, a fastener can fail even when it is correctly installed. Failure
usually occurs during torquing, but it can occur several days later. Failure of a
fastener can result in a high velocity projectile. Therefore, it is a good practice to
avoid stationing personnel in line with or below assemblies that contain large or
long fasteners.
Practice good
housekeeping
Keep the floors in the work area clean. Hydraulic fluid that is spilled on any type
of floor can result in a dangerous, slippery surface. Do not leave tools, fixtures,
or other items not specific to the test, lying about on the floor, system, or decking.
Protect hoses and
cables
Protect electrical cables from spilled hydraulic fluid and from excessive
temperatures that can cause the cables to harden and eventually fail. Ensure that
all cables have appropriate strain relief devices installed at the cable and near the
connector plug. Do not use the connector plug as a strain relief.
Protect all system hoses and cables from sharp or abrasive objects that can cause
the hose or cable to fail. Never walk on hoses or cables or move heavy objects
over them. Consider hydraulic distribution system layout and route hoses and
cables away from areas that expose them to possible damage.
When removing hydraulic hoses for equipment repair or changing testing
components (for example, hydraulic grips), make sure to cap the hose ends to
avoid spilling hydraulic fluid.