Percussion drilling is employed when auger or wash boring is not possible in very stiff soil or rock. It also can be used in most soil types.
Here the advancement of a hole is achieved by alternatively lifting and dropping a heavy cutting or hammering bit that is attached to a rope or cable that is lowered into an open hole or inside a temporary casing (casings are hollow cylindrical pipes used for borehole stability and to prevent the loss of drilling fluid through the boreholes).
Usually a tripod is used to support the cable. The stroke of bit varies according to the ground condition. The major disadvantage of this method is that it is not possible to get good-quality undisturbed samples. In very hard rock (and especially fractured hard rock), down-the-hole (DTH) drilling can be employed. In this case the hammer, applying repeated percussive pressure, is located just behind the drill bit inside the hole, unlike the open percussion drilling, where the hammer is on top of the drilling string.
The drilling string provides the necessary force and rotation to the hammer and bit, as well as compressed air or fluids to the hammer and for the flushing of cuttings.
This arrangement also allows for much deeper percussion drilling. However, the DTH drills are typically more expensive.
Percussion Drilling Rig,Cable Percussion Drilling,Percussion Drilling Equipment,Deep Foundation Engineering Percussion Rig Henan YK Prospecting Machinery Co., Ltd , https://www.yyundergrounddrillingrig.com
Marine valves
Main Products:
A) standard marine-purposed butterfly valve
B) blind plate valve
C) lifting stop valve
D) check valve
E) gate valve
F) sea valve
G) valve chest
H) quick close valve
I) storm valve
Additional Specification:
With nominal diameters of DN6MM-DN750MM,
Nominal pressure PN0.1Mpa-PN6.4Mpa;
Certificates:
It has certified by some authoritative ship classification societies such as CCS, GL, BV, DNV, KR, ABS, ISO9000: 2000 Quality system;
Air pipe head is certified by CCS, KR, GL ISO9000: 2000 Quality system.
How to order:
1) Mounting type:
2) Flange standard: S-ISO/J-JIS/G-GB etc.
3) Materials of valve seat: Buna-N rubber?
Fluorinel-containing Rubber?
Or tetrafluoro thylene containing rubber?
4) Materials of Valve body: Cast steel?
Cast Iron?
Ductile cast iron?
Bronze?
Stainless steel?
5) Nominal diameter: DN(mm)
6) Nominal pressure PN (mpa)
7) Operating type: Handle manual?
Worm manual?
Spiral operating manual?
Electrodynamic type?
Pneumatic type?
Hydraulic type?
8) Structure type: Centric Type?
Double eccentric type?
JIS F7301 Bronze 5K Globe Valve
DN
L
H
Connection Dimension of Flange
Handwheel's Dia.
Stroke m
D
C
t thickness
n-d
Do
S
15
100
130
80
60
9
4-12
80
8
5
20
110
140
85
65
10
4-12
100
10
6
25
120
160
95
75
10
4-12
125
10
8
32
140
170
115
90
12
4-12
125
10
11
40
160
190
120
95
12
4-15
140
12
14
50
210
235
130
105
14
4-15
140
12
21
65
250
260
135
130
14
4-15
160
14
26
The products are applicable for preventing refluence in fuel oil, lubircating oil and water piping system at temperature not higher than 120 c.deg. All material and dimension conform to JIS standard.
QUALITY IS OUR CULTURE.
IF YOU ARE INTERESTED IN OUR PRODUCTS, PLEASE FEEL FREE TO CONTACT ME.
December 22, 2023