Type DC - Female QD Coupling to block off cap. Similar to the B and D but just a blank block off. They're sold as duct caps but it's also a liquid tight solution as sound as any other coupling here. If all you want to do is keep dust out of the male parts, check out the vinyl caps below.
Our stainless steel Camlock style disconnects (sometimes called cam and groove) are the best compromise between cost and function for making and breaking connections between your vessels, chillers, pumps and hose sets. Eventually you get tired of pushing tubing onto hose barbs and adjusting worm gear clamps. These are cheaper than triclovers and all other stainless steel quick disconnect designs. Best of all, they are milspec standard around the world so you'll never get stuck with a single vendor's proprietary disconnect system and have trouble adding on to it several years down the road.
We offer a large selection of standard and custom high flow camlocks. They come standard with replaceable food grade silicone gaskets.
The "quick disconnect" or business portion of the camlock system consists of male and female parts. The male side is a cylinder with an external concave recess around the circumference and a front sealing face. Once inserted into the female coupling, a set of cammed arms are drawn back to apply pressure to the male's recess which locks the parts together and holds the male's sealing face tight to the captured gasket.
Quick Connect End Caps 
One worked, one didn't