LHC IRQ Tie Bar Redesign Using Sleeves – Preliminary T. Nicol May 25, 2007

Current tie bar installation

Preliminary analysis Assumed vacuum load: 20,000 lb total or 5,000 lb per rod (89,000 N) Maximum distance between vacuum vessel ears: 81” (2050 mm) Assume pinned ends Assume S.F. of 4 Pcr = p2EI/l2 = 20,000 lb For stainless steel the minimum value for I = 0.475 in4 Need ID = 1.25” to be compatible with current geometry Solving for OD yields OD = 1.86” so use 2” Actual I = 0.66 in4 so S.F. ~ 5.6

Attachment to existing ear

Attachment to sliding sleeve

Attachment to existing ear

Attachment to existing ear At the magnet ears, the tie bar attaches with a 30 mm bolt. The bronze to stainless interface slides during pressure loading.

Attachment to sliding sleeve Each tie bar joins at the sliding sleeve ear. This is where each is adjusted for length, preloaded slightly, then locked in position.

Typical assembly of two tie rods at each ear location

Typical assembly of two tie rods at each ear location

Typical tie rod assembly Tie rod sleeve – 2” OD, 1.25” ID Threaded insert – 30 mm thread ID, 42 mm thread OD Insert – 30 mm thread ID, 42 mm smooth OD Jam nut

Tie rod assembly using sleeves – v2

Typical assembly – v2 Outer nut omitted to prevent excessive load in the event of a cryogen spill inside the vacuum vessel

Typical assembly – v2 Nut to tighten sleeve against intermediate ear Nut to tighten assembly against vacuum vessel ear 2” OD, 1.25” ID sleeve Tie rod, nuts, and spherical washers are the same as those in the current system Spherical washers Tie rod

Typical assembly – v2

Typical assembly – v2

Typical assembly – v2

Q3 to DFBX tie rod assembly using sleeves – v2

Q3 to DFBX typical assembly – v2

Q3 to DFBX typical assembly – v2

Q3 to DFBX typical assembly – v2

Q3 to DFBX typical assembly – v2

Q3 to DFBX typical assembly – v2

Q1 to Q2 tie rod assembly Typical end detail MB-390923 (420 mm sleeve) 30 mm tie rod Typical end detail Spherical washers (2 pairs) 30 mm hex nuts (2) 30 mm jam nut (1)

Q2 to Q3 tie rod assembly Typical end detail MB-390924 (620 mm sleeve) 30 mm tie rod Typical end detail Spherical washers (2 pairs) 30 mm hex nuts (2) 30 mm jam nut (1)

Q3 to DFBX tie rod assembly MB-390926 (682 mm sleeve) 30 mm tie rod Stiffener plates (2) Typical end detail Spherical washers (2 pairs) 30 mm hex nuts (2) 30 mm jam nut (1)