A training manual in conducting a workshop in the design, construction, operation, maintenance and repair of hydrams
 Session 10: Hydram construction - concrete (18 hours over a 7 day period)
 Handout 10A: Concrete hydram design parameters Handout 10B: Thickness of the impulse valve plate - inches Handout 10B: Thickness of the impulse valve plate - metric Handout 10C: Impulse valve steel backing - inches Handout 10C: Impulse valve steel backing - metric Handout 10D: Impulse valve seat width - inches Handout 10D: Impulse valve seat width - metric Handout 10E: Check valve backing thickness - inches Handout 10E: Check valve backing thickness - metric Handout 10F: Check valve seat width - inches Handout 10F: Check valve seat width - metric Handout 10H: Exploded view of 2- piece concrete hydram Handout 10I: Side view 2-piece concrete hydram Handout 10J: Two piece concrete hydram form Handout 10K: Two piece concrete hydram Handout 10L: One Piece Concrete Hydram Form Handout 10M: Problem Handout 10N: Materials and procedures

Handout 10A: Concrete hydram design parameters

 CAVITY WALL THICKNESS DOME COVER THICKNESS NUMBER OF BOLTS AND SIZE

The side wall thickness (Ts) in a concrete Hydram without reinforcement shall be equal to the diameter of the cavity (Dc) in inches times the drive head (H) in feet divided by 10 or shall be equal to the cavity diameter, whichever is greater.

The top or bottom wall thickness (TL) should be 1.25 times the cavity diameter.

Concrete hydram design parameters

The total bolt area (TBA) should equal the drive pipe diameter (inches) squared times the drive head in feet divided by 50 or :

If D in mm. and H in meters then

To determine the proper number of bolts, find the area of the bolt size you wish to use and divide it into the total bolt area.

Diameter of bolt:

 mm. 6.3 8 9.5 11 12.7 14 2 15.8 19. 22.2 25.4 in. 1/4 5/16 3/8 7/16 1/2 9/16 5/8 3/4 7/8 1

Area of bolt:

 0.027 0.045 0.068 0.093 0.126 0.162 0.202 0.302 0.419 0.551