Rapidrop RD041 CUP is Quick Response frangible glass bulb automatic sprinkler. RD041 is LPCB, CE and UKCA Certified, standard orifice fire sprinkler for installation in fire sprinkler systems. In a fire condition the heat causes the fluid in the glass bulb to expand which shatters the glass and releases the seal assembly. Water flows from the orifice onto the sprinkler deflector which diffuses the water into a uniform spray pattern which extinguishes or controls the fire. Sprinkler produces a spherical water distribution pattern below the deflector.