20 3/4-3000PSI double Ram and single Ram BOP

Cameron type 20 3 4 3000PSI double Ram and single Ram BOP made in China Chinese manufacturer BOP

1.1. Technical Parameters of the Ram Blowout Preventer

Table 4 Parameters of Ram Blowout Preventer

Item	Single Ram Blowout Preventer		Double Ram Blowout Preventer
Model	20 3/4″-3000psi		20 3/4″-3000psi
Top Connection	Studded	Flanged	Studded	Flanged
Bottom Connection	Flanged	Flanged	Flanged	Flanged
Weight Kg	5980	6345	11675	12040
Length (L) mm	3550	3550	3550	3550
Height (H) mm	815	1060	1325	1570
Width (W) mm	1461	1461	1461	1461
Bore Size	527 mm (20 3/4″)
Shell Test Pressure	31.5 MPa (4,500 psi)
Rated Working Pressure	21MPa (3,000 psi)
Hydraulic Control System Test Pressure	31.5 MPa（4,500 psi）
Hydraulic Control System Working Pressure	21 MPa（3,000 psi）
Recommended Hydraulic Control Operating Pressure	8.4～10 .5 MPa(1,200～1,500 psi)
Opening volume for one set of Ram	53.9L
Closing volume for one set of Ram	56.2L
Hydraulic Port	1"NPT
Side Outlet ^note	4 1/16″-5000 psi（or customer option）
Temperature Grade ^note	T20(-29～121℃) （or customer option）
Closure Ratio	1：10.8
Other Descriptions: The blowout preventer is designed and manufactured in accordance with the API Spec 16A edifications. The internal parts of the blowout preventer in contact with the well bore fluids conform to the requirements specified in NACE MR-01-75.

Figure 1 20 3/4″-3,000 PSI Single Ram BOP

Figure 2 20 3/4″-3,000 PSI Double Ram BOP

2. Working Principles

2.1. Principles of opening and closing

When high pressure oil of hydraulic control system comes into the left and right closing chambers of cylinders through oil channel inside body from hydraulic port, the impelling Pistons drive ram shafts with ram assemblies to the center of wellhead along ram chamber to close the well. When high pressure oil comes into the left and right opening chambers of cylinders, the impelling Pistons drive the ram shafts with ram assemblies away from the center of the wellhead to open the well. The opening and closing is controlled through the reversal valve of the hydraulic control system.

██ Rams closed, bonnets opened

██ Rams opened, bonnets closed

Figure 3 Hydraulic system opening and closing drawing of rams & bonnets

2.2. Principles of well pressure sealing

A ram blowout preventer can only effectively close a well when all the four seals have taken effect. These four seals include the seal between the ram top seal and the body, the seal between the ram front seal and the pipe, the seal between the body and the bonnet, and the seal between the ram shaft and the bonnet.

The ram sealing process is divided into two steps. In the first step the hydraulic oil forces the ram shaft to impel ram packer to deform and seal the front part, and top seal seals top with compressed rubber, so it establishes a primary sealing. In the second step, with the help of the pressure inside the well the rams are impelled from behind to make ram packer deform more and the rams are also impelled from the bottom to let the body adhere tightly to top, thus achieve the reliable sealing. It is called the well pressure assisted sealing effect.

3. Structures and features

Special features

Ø The opening and closing for both rams and bonnets are all actuated hydraulically by one and same hydraulic path. The bonnets’ opening and rams’ closing are actuated by one and same hydraulic path and action; then the bonnets’ closing and rams’ opening are actuated by one and same hydraulic path and action

Ø Ram assembly: ram bodies are in long-round shape. Ram rubber is divided into two parts: front packer and top seal. This structure is easy and convenient for ram rubber to change. The front packer and top seal could be changed rESPectively according to damage condition in fact.

Ø Between body and bonnets, a floating well-pressure-assistant-sealing structure is used on bonnet. So need less pre-tighten force is needed, and it’s reliable.