Extended coverage ordinary hazard horizontal dry type sprinkler and system

A fire protection system installation for fire protection of an ordinary hazard beneath a sloped ceiling adjacent a vertical back wall, the ceiling having a slope defined by a maximum rise of four inches per one foot of run the system comprising:

• a liquid supply;
• and
• at least one sidewall sprinkler installed along the backwall beneath the ceiling, the sprinkler including:
• a tube having a proximal end and a distal end, the proximal end of the dry tube for connection to a liquid supply, the tube defining a dry passageway along a longitudinal sprinkler axis when the sprinkler is unactuated and providing communication of the liquid between the proximal and the distal end when the sprinkler is actuated;
• a sprinkler body coupled to the distal end of the tube, the body including a frame and a pair of frame arms extending distal of the frame, the frame defining an outlet in communication with the passageway for discharge of the liquid when the sprinkler is actuated;
• a deflector coupled to the frame arms and distally spaced from the outlet for distribution of the liquid discharged from the outlet, the deflector including a canopy portion radially spaced from the sprinkler axis, the sprinkler being installed such that the canopy portion is substantially parallel to the sloped ceiling so as to define a space therebetween of about six to twelve inches (6 in.-12 in.), wherein
• the liquid supply to the inlet of the at least one sprinkler being provided at a minimum pressure such that upon activation of the at least one sprinkler defines a minimum flow rate of the liquid ranging from about 38 GPM to about 64 GPM and a length of throw of liquid deflected off the deflector of about 16 FT to about 20 FT.

A method of fire protection for ordinary hazard occupancy having a ceiling and a backwall, the method comprising:

• mounting at least one sidewall sprinkler having a deflector in a horizontal orientation along the backwall of the occupancy such that deflect defines a deflector-to-ceiling spacing of about 6 in. to about 12 in, the sprinkler having an actuated and an unactuated state;
• coupling an inlet of the sprinkler to a liquid supply such that there is a dry passageway ranging in length from about 4 inches to about 48 inches between the inlet and the deflector when the sprinkler is unactuated, the coupling further providing fluid communication between the inlet and the deflector when the sprinkler is actuated;
• and
• providing a coverage area ranging from about 256 square feet to about 320 square feet.

A method of operating a dry sidewall sprinkler having a sprinkler body defining a sprinkler axis and including a frame defining an outlet and a pair of distally extending frame arms that converge toward the axis to define a frame window, the sprinkler including a seat member disposed in the outlet having a proximal surface and a distal surface, the method comprising:

• locating the seat member in the frame window;
• engaging the pair of frame arms with two points along the periphery of the distal surface of the seat member to define a pivot axis substantially perpendicular to the sprinkler axis;
• and
• rotating the seat member about the pivot axis with fluid discharge from the outlet to eject the seat member from the window.