User guide

Valves 11
Advanced User Guide 347
Load time Time in minutes that the valve remains in the Load
position before becoming ready.
Inject time Time in minutes that the valve remains in the Inject
position before returning to the Load position.
The sampling valve cycle is:
1 The sampling valve rotates to the Load position. Load time
begins. Valve is not ready.
2 Load time ends. The valve becomes ready.
3 If everything else is ready, the GC becomes ready. If anything
is not ready:
• If you are using Clock Table or sequence control, the GC
waits until everything is ready, then executes the valve
inject command.
• If you are not using Clock Table or sequence control, the
valve injection can be made at any time from the
keyboard.
4 The sampling valve rotates (keyboard command or sequence
control) to the Inject position. Inject time begins. The run
begins.
5 Inject time ends. Return to step 1.
Multiposition stream selection valve with sampling valve
Several manufacturers provide multiposition stream selection
valves that can be driven by valve drivers 1 through 4. Only one
multiposition valve can be configured.
If a valve is configured as a multiposition valve and has a BCD
position output connected to the GC, the valve position can be
selected directly.