away from the valve seat 50 and fluid flow into the chamber 60 increases the resiliency of diaphragm 20 provides its central section the self restoring flexibility to respond to the pressure of the fluid in the fluid pressure sensing chamber 60 consequently diaphragm 20 is an active member responsive to pressure changes without the need for a conventional spring the valve stem and the valve may be made of the same material as the diaphragm 20 and the valve member 80 and may be made as a one piece unit however a valve stem 75 made from a material stiffer than that used to make the diaphragm 20 is better able to maintain a constant pressure over a wider range of input pressures to increase stiffness and obtain this improved effect a rigid pin not shown may be inserted into the valve stem 75 after the diaphragm 20 is assembled into the valve body but before the adjusting cap 30 is installed alternatively the cross section of the valve stem 75 may be increased over part or all of its length to increase stiffness further the valve stem may be a completely separate part that links a separate valve element to the diaphragm the pressure regulator is useful in many applications but is particularly suited to control the output pressure of elastomeric balloon or other mechanical pumps fig2 4 illustrate an additional embodiment of a fluid pressure regulator indicated generally by the reference numeral 10 u2032 the pressure regulator 10 u2032 is similar in construction and function to the pressure regulator 10 of fig1 accordingly like reference numerals will be used to denote like components except that a u2032 will be added with similarity to the embodiment of fig1 pressure.