The lower weep hole exists to allow fluid to collect or drain out of the water pump to protect the bearing integrity. In a horizontal centrifugal pump there is little space between the bearing and the seal so fluid build-up could potentially threaten the bearing.
Definition of PETRI DISH. 1. : a small shallow dish of thin glass or plastic with a loose cover used especially for cultures in bacteriology.2. ADVERTISEMENT.Julius R. Petri â 1921 German bacteriologist.. : a small shallow dish of thin glass or plastic with a loose cover used especially for cultures in bacteriology. 2. ADVERTISEMENT. Julius R. Petri â 1921 German bacteriologist.
1 Storing the petri dishes in the refrigerator prevents the water inside the dishes from evaporating (bacteria need a moist environment to grow). 2  It also allows the surface of the agar to harden slightly, which prevents any tearing or gouging when you transfer your bacteria samples. In a heat proof dish or bowl, stir half a teaspoon of the nutrient agar powder into 60 ml (approximately 1/4 cup) of hot water. 2  Multiply these quantities for however many petri dishes you plan on using.