Peristaltic positive displacement pump apparatus

A peristaltic pump apparatus comprising a pump head and a container for a liquid to be dispensed;

• the pump head having a peristaltic pump member and a flexible dispensing tube in a fluid connection with an inside of the container;
• the fluid connection between the dispensing tube and the inside of the container being provided by a supply tube which directly connects to the dispensing tube, wherein the supply tube connected to the dispensing tube also provides a non-return valve function in a relief flow path, which communicates the inside of the dispensing tube and the supply tube to a space external to the tubes;
• wherein an open end of the supply tube is disposed within an end of the dispensing tube to provide the fluid connection and wherein the non-return valve function is provided by a hole through a side wall of the supply tube in a region where the dispensing tube overlaps the supply tube upstream of the peristaltic pump member, whereby the dispensing tube provides a seal over the hole to prevent an ingress of fluid into the dispensing tube and the supply tube from the space external to the dispensing tube and the supply tube when an internal pressure in the dispensing tube and the supply tube in the region is lower than an external pressure on the dispensing tube and the supply tube in the region and wherein the dispensing tube allows for an egress of fluid from the dispensing tube and the supply tube through the hole in the sidewall and between the dispensing tube and the supply tube to the space external to the dispensing tube and the supply tube when the internal pressure is higher than the external pressure on the dispensing tube and the supply tube in the region.