Needle valves and multiport needle valves separate the process from measuring instruments such as pressure gauges, switches or transmitters. By closing this valve the instrument can be safely dismounted for service work like recalibration or replacement. Versions with an additional vent connection are able to vent the instrument to the atmosphere by means of the needle valve. The multiport needle valve is already equipped with two additional connections. These can be used either as vent connections or for the connection of additional instruments.