US 9,810,336 B2
Subsea BOP control system with dual-action check valve
Robert E. Smith, III, Missouri City, TX (US); Timothy Goggans, Cypress, TX (US); and Frank Harold Hollister, Sugar Land, TX (US)
Assigned to National Coupling Company, Stafford, TX (US)
Filed by National Coupling Company, Inc., Stafford, TX (US)
Filed on Sep. 2, 2016, as Appl. No. 15/255,379.
Claims priority of provisional application 62/239,085, filed on Oct. 8, 2015.
Prior Publication US 2017/0102085 A1, Apr. 13, 2017
Int. Cl. E21B 33/064 (2006.01); F16K 27/02 (2006.01); E21B 33/038 (2006.01); E21B 34/04 (2006.01); F16K 15/02 (2006.01); E21B 34/16 (2006.01)
CPC F16K 27/0209 (2013.01) [E21B 33/038 (2013.01); E21B 33/064 (2013.01); E21B 34/04 (2013.01); E21B 34/16 (2013.01); F16K 15/026 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A dual-action check valve comprising:
a body having a first end and a second end;
a first blind bore in the first end of the body, the bore having a first section open to the first end of the body at an opening in the first end of the body and a first internal diameter (i.d.), a second section having a second i.d. that is less than the first i.d., and a first inclined shoulder between the first section and the second section;
a first spring-loaded poppet valve in the first blind bore sized and configured to seal against the first inclined shoulder;
a second blind bore in the second end of the body substantially parallel to the first blind bore, the second blind bore having a first section open to the second end of the body at an opening in the second end of the body and a first internal diameter (i.d.), a second section having a second i.d. that is less than the first i.d., and a second inclined shoulder between the first section and the second section;
a second spring-loaded poppet valve in the second blind bore sized and configured to seal against the second inclined shoulder;
a first cross bore at an acute angle to the first blind bore, the first cross bore having cylindrical walls, a first end open to the second section of the first blind bore, and a second, opposing end open to the first section of the second blind bore;
a second cross bore at an acute angle to the second blind bore, the second cross bore having cylindrical walls, a first end open to the second section of the second blind bore, and a second, opposing end open to the first section of the first blind bore;
wherein the first cross bore is sized and positioned such that an extension of the cylindrical walls of the first cross bore would clear the opening in the second end of the body made by the second blind bore, and
wherein the second cross bore is sized and positioned such that an extension of the cylindrical walls of the second cross bore would clear the opening in the first end of the body made by the first blind bore.