Specification of the Graphite for the Rocket Nozzle
1 Scope
1.1 Subject Contents
The Specification specifies technical requirements, quality assurance provision and preparation for delivery of graphite for the rocket nozzle.
1.2 Application scope
The specifications is applicable to inspection and acceptance of graphite material for solid rocket engine.
1.3 Classification and type
1.3.1 Graphite for rocket nozzle is classified as:
a. Cylinder type;
b. Square type.
1.3.2 Designation of graphite for rocket nozzle is in conformity with ZBK 10001 and the types are:
a. T704;
b. T705.
2 Normative References
GB/T 2900.7-1996 Electrotechnical Terminology Electrical Carbon
GB/T 13384-1992 General Specifications for Packing of Mechanical and Electrical Product
GJB 179A-96 Sampling Procedures and Table for Inspection by Attributes
GJB 1181-91 Packaging, Handling, Storage and Transportation Program Requirements for Systems and Equipments
JB/T 8133-1995 Test Method for Physical-Chemical Properties of Electrical Carbon Product
ZBK 10001-1988 Product Classification and Model Compilation Method of Carbon Graphite
3 Requirements
3.1 Qualification
Graphite material submitted in accordance with the Specification shall pass qualification inspection or type approval.
3.2 Reliability
Normal losses and service life of ablation graphite sheath and throat insert of rocket engine shall be ensured.
3.3 Materials
The graphite for rocket nozzle shall be made of aggregate of easy graphitization, high strength and ablation resistance, like petroleum coke and adhesive with high coke separation.
3.4 Structure
The cylindrical and square graphite material shall be uniform in structure and the inside shall be free from crack and cavity with diameter larger than 2mm.
3.5 Performance
3.5.1 Technical performance shall meet the requirements of Table l.
Table 1
Type Volume density g/cm3 Compressive strength
MPa Rupture strength
MPa Resistivity
μΩ·m Ash content
ppm
T704 ≥1.84 ≥2 ≥20 ≤10.5 ≤400
T705 ≥1.84 ≥42 ≥22 ≤10.5 ≤300
3.5.2 Special technical requirements, if any, may be specified in the contract.
3.6 Boundary dimension
3.6.1 The dimension and limit deviation of cylindrical graphite material shall meet the those specified in Table 2.
Table 2 mm
Outside diameter Inside diameter Height
Nominal dimension Limit deviation Nominal dimension Limit deviation Nominal dimension Limit deviation
380 +10 — — 120 +10
300 +10 — — 240 +10
230 +5 110 -5 190 +5
230 +5 110 -5 140 +5
230 +5 110 -5 110 +5
180 +5 65 -5 135 +5
180 +5 — — 200 +5
135 +5 65 -5 180 +5
90 +3 — — 180 +5
3.6.2 The dimension of square graphite material shall be specified in the contract or order.
3.7 Appearance quality
3.7.1 Graphite material shall be free from visual vertical and horizontal cracks, oxidization and holes of over 2mm high or holes with diameter larger than 2mm and uneven material density.
3.7.2 Graphite material shall be free from missing corner over 3mm long and missing arris.
3.8 Marking
Each piece of materials shall be marked firmly, including the information as follows:
a. The year of manufacture;
b. Manufacturing batch number;
c. Material number;
d. Manufacturer name or code.
4 Quality Assurance
4.1 Inspection responsibility
Unless otherwise stated in the contract, the manufacturer shall be responsible for all the inspections stated in the Specification. If necessary, the purchaser or superior appraisal institution is entitled to inspect any inspection item specified in the Specification.
Unless otherwise stated in the contract, graphite material submitted must be in accordance with those specified in Chapter 3 and Chapter 5. The inspection stated in the Specification shall be an integral part of entire quality inspection system or quality assurance program of manufacturer. The manufacturer shall also ensure that the products submitted for acceptance shall meet the requirements of the Specification or the contract.
