Page 191 - Well Control for Completions and Interventions

Well Control Surface Equipment 183

Return line
Bell
nipple

Float Trip tank level indicator
Fill up line

Pump
Trip tank
Figure 4.31 The trip tank.

the mud pumps, and typically operate at much higher discharge pressure
(up to 15,000 psi), but at lower rates (6 8 bbls/min).
Positive displacement fluid pumps are described in more detail in
Chapter 8, Pumping and Stimulation.

4.13 FLANGES, RING GASKETS, AND SEALS (API 6A)

Flange connections using metal ring gaskets, sometimes called ring
type joints, are widely used for the assembly of the BOP stack, choke
manifold, wellhead and Christmas tree. Since the flange and the gasket
ring are both metal, a correctly assembled ring joint forms a robust and
resilient metal-to-metal seal. All flanges, ring gaskets, and seals used on
well control equipment, including the wellhead, kill and choke lines,
choke manifold, and the BOP stack should conform to the recommenda-
10
tions laid out in API Specification 6A and API Specification 16A.

4.13.1 Flanges
There are two main categories of flange designated by the API in specifi-
cation 6A.
• 6B flange. Connected with R or RX ring gaskets.
• 6BX flanges. Connected with BX ring gaskets.
The API also recognizes segmented flanges used with dual string well-
heads and Christmas trees.