Block
- PropertyBool VALID, telling if it's part of a validly formed multiblock
- PropertyEnum<EnumFacing.AXIS> FACING telling what axis the valve is facing (northsouth, updown, westeast)
- PropertyBool MASTER, telling if it's the master valve in the multiblock

I assume your valve stores nothing in meta
So getMetaFromState returns 0
getStateFromMeta returns getDefaulState

In your ctor you need to set your default state
setDefaultState(blockState.getBaseState().withProperty(VALID, false).withProperty(FACING, EnumFacing.Axis.X).withProperty(MASTER, false))

You fill all those details in using getActualState
query your TE
state = state.withProperty(VALID, te.valid).withProperty(FACING, te.facing).withProeprty(MASTER, te.master);

in your json
{
	"forge_marker": 1,
	"defaults": {
		"model": "minecraft:cube_column" // by default, we have a model that wants textures "side" and "end"
		"textures": {
			"side": "modid:blocks/valve_side",
			"end": "modid:blocks/valve_end_slave"
		}
	},
	"variants": {
		"valid": {
			"true": {},
			"false": {
				"model": "minecraft:cube_all", // if valid is ever false, change the model to cube all and display the invalid texture on all 6 sides
				"textures": {
					"all": "modid:blocks/invalid"
				}
			}
		},
		"facing": {
			"x": {
				"x": 90,
				"y": 90 // Global rotation by 90 on both axes
			},
			"y": {}, // no rotation
			"z": {
				"x": 90 // Global rotation by 90 on x axis
			}
		},
		"master": {
			true: {
				"textures": {
					"end": "modid:blocks/valve_end_master" // Replace the end texture with the master one
				}
			}
			false: {} // Do nothing
		}
	}
}