8 BULLETIN 1136, U. S. DEPARTMENT OE AGRICULTURE. 
f?£TUPN BEND CO/ I 
V/T/fT/CAL /?£Tl//?AT '&&VP 'tf&Ofifr CO/l 
flIETVmt &FA/D S/fAOff? CO/L 
Fig. 2. — Pipe coils used for heating dry kilns. These are designed to provide for the 
expansion and contraction of the individual pipes and for the free flow of the con- 
densed steam to the drain end. The wall coil may also be used as a horizontal coil, 
called " Z " coil. 
